My boyfriends taste in guys

so, my boyfriend and i have been together for a couple of years now but i really only recently got a grasp of what kinda guys he's in to. Me i'm the "jock" type but jut pretty average but not bad looking but he likes big burly guys, lot of hair, doesn't care about age or anything, pretty much would want to do anyone and this makes me feel terrible especially since how much he's cheated on me. what should i think about this. why does this bother me so much that he's attracted to guys that obviously not the type I am and what should I do?