Caught on LetMeJizz
It reads as candid, someone walked in on mid-act, but almost all of it is staged from the opening frame, the surprise written into the script. The fantasy is being seen, a roommate or a stranger stumbling onto something they weren't meant to find, then either watching or climbing in. What sells the whole thing is that beat of frozen reaction before it tips from exposure into sex.
590 caught videos here, all HD and all free. New ones go up daily, so check back if you don't find your scene first time around.