Well, Maybe he thinks it was a mistake for being with another girl and not you, maybe hes trying to set u up for when him and this other girl break up, so that when they do break up u will be ready to jump in to a relationship
if she brags about her new boyfriend, she is probably just making you jealous.
Then let her know of these feelings, if she still insists her feelings for another person, let her have him.
Well if you constantly think about that person then chances are....you still have feelings for them.
Give them the cold sholder and then when they start being rude u won't stand seeing their face (personal experience)
decide if the feelings they have for the ex are bigger then the feelings they have for you. Everyone always has feelings for their ex - good or bad - so when you hook up with someone you just have to be sure that their feelings for you are stronger.
If he spends time with them and is constantly talking with them or about them chances are he is still harbouring feelings for them. If you do see this behaviour and realize he does in fact still want her its best to let them go sort out their feelings as they cannot be committed to you in anyway until he deals with his feelings for her - basically you would be a rebound.
If you are still with him and he is also seeing his ex then I would leave him. I realize that may be hard but if he is seeing someone else he is cheating on you and you deserve better. But if you believe there is nothing going on between them then you should make your feelings clear that you do not want him seeing his ex girlfriend - if he chooses to ignore the way you feel then unfortunately again you will have to do what is best for you and leave. Either way the outcome seems to be the same.
they still like you and can't help getting jealous seeing you with someone new or you did something that made them mad
Make him jealous by going out with someone else, love him anyway or slap and find someone else that you can grow to have feelings for.
If they are very flirty and if you text and hearts get sent outt
because he still misses you or he hasn't found anyone else or he has found someone else but this person could be somone that you know or very close with.
probably, he probably still has feelings for you, doesn't want to let you go completely, but is seeing someone so hes just playing games, its happen to me in the past, it sucks!