What should you do if your boyfriend of seven years broke up with you seven months ago and you just found out he is sleeping with your cousin whom you are very close to?

I am sorry you have split-up, but 7 months is a long time to be split-up and some healing time should have taken place for you. However, I do blame your cousin for not being honest with you no matter if she knew it would hurt you or not by finding out she was seeing your ex boyfriend. You cope by holding your head up high, leaving the past in the past and putting some space between you and your cousin until you feel you have settled things in your own mind. She has managed to open fresh wounds for you and she was selfish by not telling you. Don't bother to argue with your cousin about it. Start going out with your friends and getting back out in society where you are free to meet other young men. Trust me when I say, most of us have not always held onto someone we've loved when younger and we've had to heal in our own time, but move on eventually. You are stronger than you think, so get moving, get out with those friends and out in the world of the living. If you have the confidence to realize that your ex boyfriend lost out on a lot by not staying with you and that your cousin has managed to crush any trust you had between the two of you, you come out the winner! They have to deal with the way they handled this situation and there is no way in h-ll that she or your ex didn't know you were coming and they should have been more discreet about it and your cousin should have told you about seeing your ex. Some things are not in our control and for you, you had no control over this one, but you have control over yourself. Be a winner .. get moving ... get into the dating circuit again. Good luck!