OK, so practically everyone spends a lot of time on their phone, but if they're doing things that seem a bit strange, like keeping their phone flipped upside down or always taking it with them when they leave the room, those could be tiny potential indicators that something's going on.

"If your partner gets really weird with the phone, like super weird with the phone, like they make sure they always have it on them, they’re always locking it, it’s always facedown, you don’t know the passcode to the phone, they don’t leave the phone behind, they’re always walking out with the phone, they’re having conversations with the phone and you don’t know who’s on the other line, they’re texting at weird hours, that’s always a big sign in this day and age because a lot of time that we spend living, like literally living, in this day and age, is spent living through our phones, so they can have a completely second life that you don’t know about and it can all be happening on the phone, right under your nose, right next to you on the couch," Atousa Saei, a family law attorney, tells Romper.

If you feel like it's weird or different, asking them what's up might help put your mind at ease — or, unfortunately, confirm that something really is wrong.

Being reliable is a great thing, but if your partner used to be a bit more laid back and flexible and now strictly follows their new routine of coming home or calling at exactly the same time every day, that could actually be an indicator that they're trying to keep something from you.

"So if they always make the call at noon and always make the call at 3, then they don’t have to answer calls other times of the day when they’re busy doing things outside of their marriage," David Glass, PhD, a certified family law specialist and former clinical psychologist, tells Romper. "And if they always get home at 6 PM, then there’s no question as to where they are. If they always get home at 6:00, then their partner isn’t wondering where are they at 4:00, where are they at mid-morning."

Changing a social media profile picture, of course, does not necessarily mean that your partner wants your relationship to end, but shifting their social media from a focus on your relationship to a focus on just them can be a subtle sign that there's something going on and it's something that you should keep an eye out for, says Fran Greene, LCSW, a licensed clinical social worker and the author of The Secret Rules of Flirting. Greene notes that you still have the control over your profile, just as they do over theirs, but that the "dramatic change" is what's important to recognize.

Greene says that if your partner starts to regularly tell you that they have to work late or go in on days that they normally wouldn't, that can be an indicator that they want to spend some time away from you. If everything else seems totally fine, Greene says that you probably don't have to worry, but if there are other signs there too that something might be off, you should pay attention.

"The best analogy is when you really are in a good relationship, you can be totally silent with somebody and you’re not worried at all," Greene explains. "When there’s anxiety and worry, the minute there’s no talking or touching, it’s like, ‘OK, what’s wrong?’"

It's normal to think that you'll likely do something fun with your partner over a long weekend or that you might at least discuss what you're going to do for certain holidays. Greene says that this is especially significant if you're dating. If they can't tell you what they're going to be doing or don't want to make plans for a long weekend that's coming up, that might be a sign that they're not as fully invested in the relationship as you might think.

"If ordinarily you have a 401k and you have a bank account and you have a brokerage account and maybe some life insurance policies and a mortgage on the house, most people don’t keep track of those things on a day-to-day basis, but suddenly your partner starts asking a lot of questions, ‘Where do we have that 401k?’ and ‘What is the homeowner’s insurance?’ and ‘What do pay for this mortgage?’ and they start collecting and ‘Where do we keep our last tax return?'" These are all documents that divorce lawyers will typically ask for in an initial consultation, so that’s when they have a potential client coming in, they can get an overall picture of a family’s finances," Glass says. So you might not think that this is potentially anything other than them wanting to understand your shared financial situation a bit better, but it could actually be a hint that they're considering ending things altogether.

Glass recommends bringing up your concerns with your partner sooner rather than later, speaking simply, and really listening to what kind of answer (or non-answer) they give.

Whether you're not being invited to things as a couple anymore or they just don't want to go to events as a couple anymore, that can be another sneaky sign that something might be going on. "Because at social events, you’re a couple, it’s a statement," Greene says. So if they're having doubts about whether the relationship is going to work out or they're considering ending things, they might not want to send any sort of message like that to family, friends, or coworkers and colleagues.

If your partner is doing something wrong, they might try to accuse you of doing that same thing. That's what's called projection and Glass says that that can be another sign that something is amiss. "So if someone is having an affair or is flirting, [they] will suddenly start accusing their partner," he explains. "‘You were awfully friendly with that waiter (or waitress)’ or, ‘I saw the way that you were talking to that other mom (or dad) at school,” and it’s a way of them relieving their guilt — they try to put that guilt on the other party, whether it’s really happening or not."

Greene says that if you share information with them that you're excited about, like finding the perfect outfit for an event that you've been looking for for weeks or your boss giving you a major compliment after months of feeling like you weren't doing enough, and they can't muster more than an indifferent response, that can also be a sign that something might be wrong. They're not always going to be as excited about everything as you are (and vice versa), but recognizing that this is something that matters to you is important.

It's good for you to do things without your partner from time to time, but if the only way they can make plans now is by encouraging you to do things on your own, that's likely not a great sign, Greene says.

"‘You know what? You can go to your sister’s for the weekend.' Or, ‘You know? Going to that engagement party? I don’t really know anybody, you can just go by yourself,'" Greene explains. "Or ‘You’d much rather see Summer [The Donna Summer Musical] with a girlfriend, I’m not really a disco fan, that was before my time,’ when, in the past, your partner would say, ‘You know, I’m not into it, but I want to do something that you really like doing.’"

Sometimes that's part of relationships, doing something because it's something your partner enjoys, and if they can't do those kinds of things anymore, that might mean that they're considering a split.

"I’ve had a lot of my clients over the last 21 years of being a divorce attorney saying that their partner suddenly did not find other people’s affairs as offensive," Glass says. "So if they’re watching Entertainment Tonight or Extra or something on TV and they report on the affair of a celebrity, where that person normally would not comment on it or be offended by it, they’re now saying, ‘oh, well, they must have had a lousy marriage’ or ‘they must have not been happy at home,’ or ‘well if you don’t get it at home, you’re going to go looking somewhere else,’ and that sort of attitude change about other people’s lifestyle and other people’s affairs often reflect on how they’re feeling about where they stand in their own relationship."

This is something that's extremely subtle, but taking note of how they react to things like this might give you some insight into how they feel about it in terms of themselves and your relationship, as well.

You don't always have to be the very first person they tell things to, but you're probably typically told things early-on. Greene says that if you now find that your partner is telling other people things and going to other people for advice on subjects when they used to turn to you, that can also be a sign that something isn't right.

Greene says that telling your partner how you're seeing the situation and asking them if there's anything wrong or anything they'd like to tell you can help jump-start the conversation and might help you both come to a better understanding of one another (even though it's a scary thing to ask).

"If you’re in a serious relationship, you get pretty well-versed to know how your partner’s communication style is and how they speak to you and you can tell when something’s off," Saei says. "So if their language completely changes with you, and they’re short with you, or they speak to you in a way where they’re not as engaged as usual, or they’re not really interested in having long talks with you or talking to you about their day, and using less detail in their language with you, that’s another sign."

Again, what's important here is the change. Greene notes that things can sometimes happen — maybe their phone battery died or they were in a building with terrible service, for example — and so keeping an eye out for the patterns that develop or change can help you determine if it was nothing, or if it might be something you need to address.

If everything you say results in a challenge from your partner because they disagree with it, that's not a sign that things are going great between the two of you. "If you find that, no matter what you say, your partner is challenging you or disagreeing with you or negating everything that you’re saying, or ridiculing you, it’s this feeling of tension," Greene says. It could be a sign that they're rethinking the relationship.

If your partner changes the way that they spend money on you, your relationship, or your home together, that too might be a sign that they have one foot out the door, Greene says. They don't want to financially invest in a relationship that they think is over or will be soon.

Being open and honest with your partner about what you're seeing, feeling, and experiencing is important. It can help you figure out if there's something to this or not. It can also help the two of you strengthen your relationship, even if it doesn't feel like it will when you're worried they're not going to stick around. Addressing things with your partner in a way that they'll hear you is also important. Working with a professional can help you navigate the situation and figure out what the future might really hold, whether that's the two of you together in a relationship or apart.