six is part of the human (and orc, and elf, etc.) condition. adding six in a mature and tastefully handled way would enhance the realistic aspects of the game. Having said that, it needs to be equal. Morrowind had romance quests, but only if your character was male. The ladies had to be content with a kiss from Nels Llendo
If your male character can have romance/visit a courtesan or hoker/have a hook-up, then your female characters should have that option too, with equally attractive partners. I've played too many games where male characters get a hottie, but the females get a nottie
There is a bordello in Neverwinter Nights where male and female characters had equal access to equally appealing partners, and it was tastefully handled.
six and erotic content in games isn't immature, but it sometimes gets the immature treatment. I am not sure how to explain this in a way that won't offend someone or break the rules, so I am going to stop now.