I'm so sick of the whole "I only slept around because I liked you but were killing time un...

I'm so sick of the whole "I only slept around because I liked you but were killing time until we got together"... And of course it's always the guy who says that and is instantly "forgiven" by the girl. I wonder how the guy would react if it was the girl who had slept around and he was a virgin. Have never seen a manga like that though because these girls almost always gets portrayed as being a "bitches"...