Actor Robert Downey Jr. has stunned Hollywood with a wild accusation -- that many movies' leading men "go to bed" with their female co-star.

Downey openly admits he's indulged his sexual desires on movie sets in the past, and insists such intimate activity between co-stars is inevitable, because they spend so much together in such a close environment.

He tells the Scottish Daily Record, "I remember certain colleagues having a lot of fun on the set with me.

"Every second star goes to bed with his co-star because they spend so much time together. But I'm not going to start reeling off the names."