Let's be honest here: The primary payoffs we're wanting here are a) vaginal sex with Lisa, and b) vaginal sex with Mom, and some people are hoping for a c) Max fathering between one to four children.
I agree with a previous poster: Lisa's appeal is love & romance. While Max is a horndog, I believed in the beginning that he saw himself as boyfriend material for her. I'm not sure if that can be gotten back now.
And sex with Anne/Mom, vaginal and/or anal should happen in a movie at some point. But to break down the barrier, Max should arouse her to the point where she no longer objects. Maybe fingering her in her sleep, followed by cunnilingus, then maybe grinding genitals, and (remember that Anne loses her inhibitions when she's extremely aroused?) eventually Mom says, "Fuck me!" and throws caution to the wind. Afterwards, she'll try to deny it, but no doubt Max can lay pipe better than Eric or his Dad ever did, and she'll come sniffing around him every time she has an itch that needs to be scratched.
Added: Oh, yeah! Some kissing, please?! I don't know about you, when I have sex with a woman, I kiss her! I sometimes put my head to the side of hers. I sometime suck on her tits. But I always kiss her. It doesn't have to be a "love" thing, it's a passion thing. She wants it. She needs it.
And it doesn't suck for me, either.