To trigger other sex scene like vaginal sex or blowjob, player need to enter the sex scene first, and switch the scene vie the UI for the sex scene.
Now I've seen that the pattern might be too concealing; it could use a change by adding those choices to the interaction UI to make it more intuitive.
I'd say it absolutely could use a touch up- because the possibility that it existed within the scene itself crossed my mind while I was looking at it but I could not find it. I'll have to take a look again and see where it's actually hidden.
I do really like what you got so far though, and I look forward to more!