Why does my Girlfriend feel the need to dance with other guys?

ok before i start let me clarify the only form of dancing i dont like my girlfriend doing with another guy is grinding. for those of you that dont know what that is, its literally grinding your body on another persons body while dancing, usually the girls ass on the guys penis.

ok so i was having a conversation with my girlfriend. and i was making plans for tonight. i said lets go to a club, and she seemed hesitant, i kept asking lets go and she said no finally, i said why, she said becuase your just going to get mad. she said i dont want to dance with one guy all night i want to dance bachata and salsa with other guys. which i dont mind becuase its not so close.

so im wondering ladies, if your boyfriend has a problem with you dancing with other men why is that such a problem. like is it ABSOLUTELY necessary that you have to dance with other men? youd rather stay home and watch tv then go out just becuase you cant dance with other guys without your boyfriend getting upset??