Their body their choice.

Just because you don’t like how someone has sex doesn’t mean you have any right to prevent them from doing it.

What you do have a right to is a right of quiet enjoyment of your lease. OP can’t stop them from having sex or RP’ing but she can ask them to keep it down, protest this with the LL and threaten to move out due to an inability to enjoy the lease.

She’s already tried talking to them but they don’t have to have a ‘free sex zone’ just because OP isn’t comfortable with it. It just makes them assholes about it because they have two places they can have sex and OP only has one place to live.