Yeah, I could really care less to see any lesbian stuff, incestual or otherwise. It would be a waste of rendering time as far as I'm concerned. I'm sure others would like it, but I'd prefer for the sex to all involve Max.
From my point of view, that would be awful. Then you would have already had sex with your mom (Kira) without knowing it, and the fun of going after Lisa and Ann is cut immensely with them being "downgraded" to cousin and aunt respectively. It would be only slightly less game-killing than finding out Max was adopted.