Ah, I have used the lust witch to start off a couple times. But I like to use the fallen keeper to start off using the lust mechanics in game. Breeding the female dwellers on my own is fine, but I have my dwellers to breed with each other too other than just myself to keep things fun and fresh. All species welcome. No clothing restrictions but loincloths and rags are encouraged~.
For the new update I can't seem to make the npcs mate with each other, probably not implemented in game yet. Good thing I didn't delete the previous version of the game. Though I have seen NPCs have sex with each other in the current version, but its mainly oral, nothing else.