With the mainstreaming of XXX films, we've seen a lot of adult stars—Sasha Grey, Jenna Jameson, James Deen—surfacing in non-adult movies, often simply for the novelty.

But there are other stories in Hollywood of actors crossing over under different circumstance—whether it be successful screen icons with early-career adult-film-dabblings or child stars who ended up doing the deed on camera just to pay the rent. How did these people get into the X-rated industry, and how did others get out?

Read on for the answers, and more, in this list of 15 mainstream actors who've done adult films.