It sucks... At least you know the man you are with. I am sorry but if someone can go over a month with sleeping with someone else while in a relationship... That says all I need to know about this man you are with. You choosing to stay... Now that will determine the man you are. One that is alright with this, Or one that will not be disrespected.

the only fuck up is your ex cheating on you. THat is all. I am sorry and hope you find love for you