What is this a Frazetta painting?
She was a SLAVE. In order to please her master she needed to please the man she was sent to sleep with. Her master could have her killed any time he wanted to.
Kirk could have threatened her with death if she didn't try to please him. He didn't. A womanizer would have used that to his advantage.
The fact is, though, that she was a slave. Kirk was going to die the next day. Kirk refused at first, on the grounds that he believed it was all a setup. Drusilla convinced him otherwise. Even though there is
room to say that they had sex, there's just too much open to interpretation to say what all was involved, and how mutual it was. I even went back and watched that scene in the episode before I responded, just to make sure my retelling of the events was accurate.