quick google says laws vary by state (ok, no shit). Generally it is legal to film without consent if it is in public and there is no expectation of privacy. On private property, there can be an expectation of privacy so it is not legal. On top of that, some states have specific laws that make filming someone in certain situations a form of sexual harassment.
So my humble bet - a bedroom has an expectation of privacy and filming would require consent to be legal. Add to that sharing the photos (even if you did not take them) can be sexual harrasment in some places.
I know of a story that was fairly close to me, abet rather indirectly. A frat boy lost some money at poker in Austin, so he made some amateur porn with his girlfriend (without her knowledge and shared it with his Frat brothers to pay off his gambling losses. She found out and sued him. The tapes were entered as evidence - and the lawyers decided they were good enough to be shared as well. The Lawyers got sued too. It was kind of close to me because I knew the person who owned the condo that the frat boy was renting and where he filmed them. I don't think the condo owner was sued.
It was a big enough scandal that even though it happened at UT, it was mentioned in a law course I took at a different University.
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My family also researched this a bit when we put in security cameras outside a vacation rental owned by the family. The cameras can not see anything that can not be scene from the streets for the most part (perhaps there are a couple of inches close to the deck that might be hard to see from the street as our cameras face down not up). But the cameras are obviously placed and not hidden. So far we have not recorded anyone having sex - but we have seen people running around naked outdoors. Likewise, I think we have only recorded trespassers doing shit, not renters...