The movie star was shooting an erotic dancing scene in a club full of lusty extras when his thong slipped away — and rather than stop filming, director Steven Soderbergh gave McConaughey the signal to keep dancing.
The actor tells Entertainment Weekly magazine, "I stayed in sequence. I went for the tuck. I went for the roll - and I finished the dance."
Co-star Joe Manganiello admits he was amazed there weren't more unscripted full frontal moments - because the women brought in to lust after himself, McConaughey, Channing Tatum and Matt Bomer were wild.
He adds, "The women are crazy... There are husbands who are going to divorce their wives when they see what their wives were doing as extras on this movie."