Actor here. Doing intimacy scenes is surprisingly difficult, arguably more so than combat, because usually people train and get certified in sword and dagger, rapier, firearms etc to get cast
When working a job, putting your mouth on another person’s mouth is a very unusual act, and you want your actors - regardless of gender - to feel safe, comfortable, professional and not exploited - not to mention you might spend 2x 14 hours days on this sequence from multiple angles getting it the same every time