They will act different the regularly
if she brags about her new boyfriend, she is probably just making you jealous.
Most likely, they will tease the hell out of whatever they are jealous of you for.
He does everything in his power to let you know that he is remorseful, and doesn't do it again
If you are with someone else then it really should not matter what your ex thinks either way. If you are trying to make him jealous and just using someone to do so that is wrong and not fair to that person. If your ex is jealous you will know by the way he treats you.
show him what hes missing make him jealous ;)
If you are jealous, you have a feeling you need to follow - what about him and his situation is making you jealous - jealousy is a feeling that lets you know what your emotions are lacking in your everyday relationships.
Not sure how you expect someone to magically know something.
People are jealous because someone else is getting something or even someone that they cannot get.
If he is making you jealous just ask him out your self if you know he is not going to ask you out!!
The cast of Jealous Making - 2013 includes: Guy Mannerings as Patrick
Make him/ her jealous.