Yup! Side girls will be able to get pregnant :)
I was planning on adding it to Act Two before I created the finale, but it was taking too long to get to Act Three so the side girl pregnancy thing has been put on the back burner for now. Might show up in Act Three, but more likely I'll add it to Act Two once the game enters beta.
Ard becoming gay through waking up on top of the MC probably won't happen, for the simple reason that that's not how being gay works ;)