Is it bad?

So today I was playing truth or dare with my friends and one of my friends dared me to kiss a boy playing with us(I like him, but my bestie likes him) on the cheek. I didn’t want to lose so I did it, then found out he has a girlfriend. I know his girlfriend and she’s a really bad person, but I kind of feel bad. I didn’t know they were dating until after he said we can’t tell my girlfriend. Does that make me bad or him?!?!?