First H with them is triggered through an event. I'm not sure where you are in the story or even how you got their Love and Trust so high, but doing their events/quests and OR continuing the main story would eventually lead you to an event to get the chance to deflower them (or postpone it). After so, you can do some H with them whenever after. (I haven't played it in awhile, this is going off the top of my head)
No. Actual sex is gated behind relationship status. Make the woman your girlfriend. Get love and trust high (maybe 800?). Take her on a date. She should come to you the next day or so and tell you she's ready for sex -- after you make the night special with a regular date.
Thank you all for your answers; I was able to trigger the event, finally it worked right after a date (with girlfriend status and enough relationship points) when not inviting the girls in my room, as I had done in the last few dates in the hope of seeing the newly unlocked sex options.Anal used to be gated behind deflowering, but with the decision to make the polyamory more structured we threw you guys a bone.