The wiki has this to say about Sera:
Sera's my bitch and a crew member. I've birthed 27 of her kids and she's birthed one of mine (only one at a time, Sera? scoff!), but I don't see any option for having Sera as my sleeping partner. How do I make this happen?
And, during and after her pregnancy or your pregnancy, Steele can allow Sera to sleep with them either to cuddle with the PC at the head of the bed, or as a foot-warmer curled at the foot of the bed. During this period, Sera may automatically initiate random morning sex scenes.
Sera's my bitch and a crew member. I've birthed 27 of her kids and she's birthed one of mine (only one at a time, Sera? scoff!), but I don't see any option for having Sera as my sleeping partner. How do I make this happen?