At the moment I don't think there are any Jessica scenes I can extend to add in a sex option. Ferdafs did say that a Jessica scene was planned for this update but it didn't get finished in time... so, maybe we'll get more Jessica in the Aug/Sept update?
While I know it's not the same thing (and not what most people want),
there is the sex scene with nazi Jessica, so that's at least something. But again, my ability to add new art content is mostly limited to edits. If I could easily make my own art, I'd have just done my own game