You can make Maria suck or fuck someone. I didn't let her do that. I came to know about this from walkthrough. The whole NTR plot revolves around 2 other characters. Boy is a cuck and girl fucks around. You have the option to fuck that girl too. You're not the cuck. Some other guy is.
So it's fine if the girl is only giving blowjobs and not having sex? You'll love a good blowbang scene.
BTW why and how Pete fucked Lydia? It's bad she turned out to be a bitch. I like virgins and there are only 2 virgins. Stacy and Lydia(or so I thought. She might have lied all along).