Stop using instagram. Computers are for accountants and journalists.

Just find a hot chick's photos to like all the time. She'll figure it out once the shoe is on the other foot.

Try not to read too much into it. Is it a friend who lives elsewhere or that they don't see very much? My partner does the same with a few girls but I also know they are people he doesn't see very often or at all because they live elsewhere. I do the same with friends I don't see often.

They're sleeping together.

She thinks he's hot because she's a human being with a sex drive. Relax and remember that she chose you. If you get super pissy, she might consider leaving; but if you calmly say you're feeling insecure, she might help you get over it. Just make sure you leave her lots of room to feel attraction toward other dudes. Sometimes just having an adult conversation about your feelings is enough to help you break the spell of jealousy.

But whatever you do, avoid telling her what to do.

Women only pay attention to men they really like otherwise it's what you see around here every day. Nose up high, face tucked into a black mirror, you don't exist.

It doesn't matter if it's your girlfriend or boyfriend who does it. If you're in a committed relationship with someone, it's disrespectful to your partner to show interest in someone else (unless you're in an open relationship). It also shows a lack of consideration for your feelings. If she liked all guys' pictures, I might attribute that to immaturity, and try to talk to her, asking her how would she feel if you liked pictures of other women in bikinis. But in this case, it sounds like she systematically targets one guy in particular. It seems like she's sending him signals that she's interested in him. I would be worried that she would leave you if the guy were to return her interest. You could still try to speak to her but I'm not sure I'd want to be in a relationship with this kind of person.

This is my opinion: tell her it makes you feel uncomfortable and see what she does. If she respects your feelings she will stop immediately. If she cares more about getting attention from this shirtless dude then she will act defensive & get annoyed with you for bringing it up. If the latter happens then you need to break up because it's clear that it's over.

Duh!...Break up with her immediately. She's really mean!

First of all, sorry you're going through this. Having someone we love doing things that heighten our insecurities is super rough. Please be really lovely to yourself and remember what's great about you.

Okay, so in terms of dealing with this, you need to explore your jealousy first. What's coming up when you she that she has liked these pics? Do you feel scared that she doesn't think that you are attractive? That she's bored with the relationship you have? That she's not really into you, just staying in the relationship till the next thing comes along?

When you understand the roots of your jealousy, then you are in a place to have a good conversation about it. This can be hard though because it requires admitting to yourself what your fears actually are. Your mileage may vary and all, but best of luck. Hope it leads to a conversation that takes you to a happier place.