This isn't exactly a "freak out", but when Ann Miller did PANAMA HATTIE in Fort Lauderdale, her male co-star used to have quite audible sex with his boyfriend up against the wall that divided his dressing room from Ann's: often before the show or sometimes during intermission. When he would then kiss Ann as cued on stage, she would turn US and wipe her mouth with her sleeve. For a woman who carefully painted her teeth with cold cream before going on, I'm sure wiping her mouth was quite a concession.
And speaking of the late Roberta Peters, she was always a doll. But I did witness her conductor on THE MERRY WIDOW lock himself in his dress room during intermission and refuse to come out. Miss Peters spent the entire interval plus an extra five minutes pleading with him to return to his podium. He eventually did. To this day I wonder what could have so upset him.
I was in a production of Spelling Bee once and an old, mentally deranged ex-acting teacher of mine was chosen as one of the guest spellers and she completely hijacked the show until the actress playing Rona "disqualified" her from the competition for bad behavior at the Bee.
I heard that during previews of the 2005 Sweeney Todd revival, Patti yelled at Michael Cerveris for missing an entrance and made him start the scene over. I have no idea if it's true, but i definitely believe it!!
@icecreambenjamin, I can top that story. So in Spelling Bee, the action goes in this order.
1. Marcy spells Qaimiqam, and Rona says she's all business
2. Audience member gets out
3. Chip gets out (misspells Tittup)
4. Favorite Moment Reprise
5. Last Audience Member gets out (Prayer of the Comfort Counselor)
It's incredibly important this sequence goes in this order, because it set's up Marcy's insecurity, set's up Chip's Lament, and gets the last of the audience members off the stage. However, in our production, the guy playing Panch messed up the order, forgot to call up Marcy, gives Chip a random word (which he luckily spelled correctly), and gets both the audience members out, so we're forced to go to Prayer of the Comfort Counselor. We finally get back on track and get Chip out, but our Rona was so upset she forgot half the lyrics to Favorite Moment Reprise.