AceShowbiz - Madonna may not be the best audience member when it comes to musicals. John Benjamin Hickey recalled during his appearance on "Watch What Happens Live with Andy Cohen" the moment when he was starstruck by seeing the singing diva among the audience of his musical, only to get baffled.

"A long time ago--twenty-something years ago, at the beginning of our [Andy Cohen] friendship--I did a revival of the musical, 'Cabaret'," John told the host. "And I did it with the great Natasha Richardson and Alan Cumming. And one night in the audience, Madonna was there. And we were all so excited that she was there."

However, Madonna didn't seem to pay attention to the performance. "And there were kind of lights on the audience, and Madonna proceeded to sit and braid her hair through the entire performance," so John continued to recall.

While the "In Treatment" star said that he didn't really mind the "Hung Up" singer's behavior, some others couldn't look past that. "I didn't really give a s**t. I didn't care one way or the other. Our leading lady, Natasha Richardson, came backstage with steam coming out of her ears. 'How dare she?' And she was absolutely right," he said.

Slamming the "Material Girl" hitmaker, the actor added, "If you're gonna come to the theater, don't sit and braid your hair. Have some manners, especially if you know all eyes are on you. So, I guess that was a version of being starstruck--but not in the right way."

He also shared that he had "tunnel vision" when it comes to being on stage. "Especially if somebody famous is out there, somebody I respect a lot. I don't know if I respect her as an actor," he shared.

During the interview, John also talked about Meryl Streep. For the "Mamma Mia! Here We Go Again" star, John had nothing but positive words. "Meryl is great at backstage though. Meryl is one of those people who knows.. she knows what power she has and she gives it all in a positive, wonderful way to other actors," he gushed.