if a boyfriend or girlfriend breakup and one cheated on you ,who you love should you get back together?

a boyfriend or girlfriend cheated on you and lie and broke up and you love that person so much.
if boyfriend cheated on you twice and 1 with a girl saying the girl look like me and other with ex. and he couldnt forget about her and been depress over a month and it brought you down depress to where it got you to cut yourself and been bringing himself down even though your trying to keep them happy and he said he dated me because i remind him of his ex. and him finding out he had kids cuz his ex and him dated and she told him it was miscarriage and now tells him few months later it wasnt miscarriage. and then saying a friend of mine is dating him after the day we broke and thas when we were going to get help from my friend and she says no she not dating him, she dating a different guy thats her bf and he says he is and he saying the friend of your been threw alot of **** and now reminds him of his ex