It's happened a few times, and as I get more comfortable doing kino it is bound to come up again.
It always happens when things are really good with a girl. First time I was talking to a girl and a loser says "hand on her hip, smooth." He was cock blocking, but his comment was genuine.

the girl got embarrassed and ejected. I should have reopened, but this was a while ago. The most recent time was last night and I'm vibing out with an HB server off shift and bar regular who was sitting with her too commented when she left to to washroom that if she was behind the I wouldn't be touching her leg. "Obviously" i said, thinking it's only an issue of bad geography. She came back and he was all in a huff because of my dismissive attitude toward his obvious objection. She asked what's up and I said he had issue with me touching her leg. He rattled and jabbered on about how he doesn't like people touching his friends. Their "friendship" be that he is an old AFC dude that buys her drinks and calls her pretty.
How to best deal with random chodes messing with your interaction like this? I'm not talking about real friends with real concerns. Nor am I talking about heavy escalation; think one step past friendly but not explicitly sexual.
If they embarrass the girl by calling attention to the fact they are letting me touch them in a way the cockblocker can't do, how to recover and alleviate the girls embarrassment. How to tell the guy to mind his own business. I'm not embarrassed, or sneaky about touching a girl. Last night it was while talking to her HB bartender coworker and the owner chilling out too, and the girl was kinoing back. Everything was cherry until fuckface piped up.