Is it bad to grind with your best friends crush?

You see we were at a bat-mitzvah and we were both looking really pretty. When we start dancing we see her crush grinding with other girls so when he passes by she dances extra flirty. The next thing i know he is grinding with her. She looks pleased but after about 2 seconds he lets go and calls her the worst grinder ever. I try to make her feel better by complimenting her hair and outfit but she is still pissed so when we start dancing someone grabs me by my waist and starts grinding with me. After a song I turn around and see my best friend's crush smiling back at me with a huge *****. I said im sorry about 20 times but she said it was ok and that it was just dancing but she still looked hurt. After the party a friend was going to take all of us home. He wante me to sit on his lap. My best friend said she didnt care but what she doesnt know is that as he was getting out of the car he winked at me. Am I a bad friend? Its not like i knew who it was.