I'm sorry to interject twice on the topic, Jay. But my experience tells me the same thing. Individualism prevails.
It depends on the individual who's being shunned, and the one who's to do the shunning.
If the guy is charismatic, and the shunner is less-so, the magnetism of the dominant personality may exceed the ability to be refused.
When I was a teen, I was among an eclectic crowd. I could cross boarders pretty easily. I could go from the heads to the jocks to the geeks, and had some good ties in each crowd.
What I noticed in each group was pretty interesting. There was a couple rats to be counted in each crew. One guy had sticky fingers, another fought too easily, another couldn't be trusted among your chicks.
Yet, there they were. I knew one guy, bold as brass, who carried himself almost like Bill Clinton. Looked nothing like him, but he had a certain something that most people couldn't stay mad at, and he often did some pretty dastardly shit. One time (he drove this little 80's junker Mustang) he slammed on his brakes and got rear-ended by another friend of mine who was driving his mom's Lexus. On the way to a wedding. Called the cops, they wrote in favor of the brake-slammer, who'd done it on purpose. The Lexus dude was crying actual tears, and the front was all crushed up. $275 for brake-lights. He stole replacements from a junkyard.
Fucked my girlfriend, I let him keep her, she was no good anyway. To this day I'd still like to see him, I didn't hold a grudge. I know what to expect.
One day I scored a couple ounces and took him to my room to bag it up. Had to piss, and left all the reefer in the process.
I came back, and he was purposely sitting far away, as if to prove he didn't touch it. He looked a little misty and said "You must really trust me", I said no, I have a scale. These bags weigh. I gave him a bud for being cool about it. He tried, I knew he couldn't help himself sometimes.
The reason I kept him around was because he was fun. He knew lots of weasels. We had a lot of good times together. But I never fully trusted him. That would be stupid.