Why do guys who sleep around when encontering a woman who is not promiscuous refer to her as "loser, etc". I mean between the two - he's the loser?

Where I live cheating, multiple partners, etc. is NOT uncommon. It's a very working / low class / welfare town. I wasn't born here, I just work here as hospital staff (medical professional).

Anyway I was talking with one guy - medical - doesn't work at hospital but we've same profession --- he works with one of my own colleagues so we chat / coffee --- and when I let it out I'm not promiscuous, only been with a very few guys his response was "loser".

And I'm like okay... that's nice, stopped talking to him. We'd only gone on one coffee "date".

Why do guys who sleep around when encontering a woman who is not promiscuous refer to her as "loser, etc". I mean between the two - he's the loser?
Post Opinion