The answer depends on how truly contrite and trustworthy the boyfriend on never cheating.
bad luck
how do you know if your boyfriend has cheated
Sounds like you need a better boyfriend.
She probably feels bad after what she did to you. Even if you now hate her after what she did to you she feels the same way as he was her boyfriend too
Next Boyfriend....
tell her that her boyfriend cheated on her. she needs to know.
Dump him
you go and tell him you cheated on him and tell him how sorry you are and ask him to forgive you.
I'm sure your ex-boyfriend's unfaithfulness doesn't make you a bad girlfriend -- only him a bad boyfriend. Don't be so hard on yourself. He probably would've done the same thing to any girl.
There is no way to positively know if your boyfriend has cheated on you unless you catch him or he tells you. There may be some signs such as not being where he says he is or lying to you on who he was with.
By marrying him.
yes. Why...?