Why do boyfriends cheat?

Sometimes they are not sure how you feel about them anymore, maybe you havent said I love you, in awhile. So they feel alone and the only way they can forget about you for a moment is to cheat on you.

Because they think another girl is prettier and like her better than you but think you have a good figure and they just think that they are better thatn anyone else in the world. I THINK MY BOYFREIND IS CHEATING ON ME WAT SHOULD I DO I NOW HE LOVE ME