No topic was too sensitive for Ben Stiller and Robert Downey Jr. as they bantered while introducing two extended clips from their upcoming comedy Tropic Thunder on Tuesday night. At a party that unveiled snippets of the R-rated summer flick for ShoWest attendees, Stiller and Downey riffed on such verboten topics as jail time, drug use, and failed movies. “Hmm, Mystery Men, I don’t know that movie,” Downey said. “Oh really, maybe it came out when you were in jail,” Stiller replied. Then, later: “My kid woke up screaming in the middle of the night,” Downey said. “Oh really, why?” asked Stiller. “He dreamed we had to go see The Heartbreak Kid again,” Downey quipped. And so it went.

The no-holds-barred chitchat may have been the perfect setup for a movie that appears to defy social convention (as was the evening’s party, at the Planet Hollywood casino’s swanky sushi joint Koi, which featured erotic dancers shaking their hips in skimpy, camouflaged ensembles). Tropic Thunder centers on a group of actors (including Stiller, Downey, and Jack Black) who get dropped into the jungle by a director (Steve Coogan) who is tired of their canned performances in his Vietnam War film. Downey (as you may have read) plays a white actor who dyes his skin black for his role — and recites the theme song to The Jeffersons for added authenticity. Meanwhile, Black’s tortured thespian craves drugs and Stiller’s character eats the blood of his recently blown-apart director. Indeed, Tropic Thunder has the potential to be that outrageous summer flick that keeps audiences talking for weeks — which is exactly what Paramount will be counting on when the film opens on Aug. 15.