My fiancé and I have been together for 9yrs we have two boys together.
These last couple of years have been difficult I cheated on hI'm and felt so guilty I told him all about it, we got through it and he asked me to marry him then it started again the reason I ended up cheating in the first place, going out till all hrs of the morning every Monday and Thursday.
That wasn't a problem till he started taking it too far then I caught him txtin his friends daughter which he tried to lie about it then he bought condoms and said they wer to use with me but then I discover 4 were missing! When I confront him about it he fly off the handle refuses to give me any explanation and tells me I'm being paranoid.

You cheated on him... then he cheated on you? Relationship is not a game. Here is a suggestion: Promise means everything, once broken, sorry means nothing. Good luck.

Why do you think total strangers (us) are going to know what your man is doing?

You two are in very deep with the cheating accusations and actual cheating. It's time to really sit down and talk, without confrontation. If you can't do that (pretend there's a therapist sitting between you), then maybe this 9 year 'engagement' should end. Tell him that this is extremely important, that the talk is a turning point in your lives, and that you need to talk with respect for each other. As for why you cheated in the first place - that's not a good reason, him staying out late. Cheating for revenge is a cop out. So enter this serious talk without any notions of who is more right than the other.