I'd rather watch a porn film WITH my parents.
When I was a pre-teen, I walked into their bedroom at an inopportune time and got quite an eye full. That was more than enough!
Not sure if I ducked out quick enough before they could see I'd been there. None of us ever spoke of it.
Watching with them would also mean that my dad was still alive and that maybe they were still married. Wishful thinking...