Actually, this scene bugged me for several reasons. First, no way she takes all of MC that easy. She's only been penetrated once, and it was only part way, and she was drunk. She's displayed that she's uncomfortable, emotionally and physically, with penetration (see the dildo conversation), and she's in an uncomfortable state in this scene because they are outside and she's very anxious about getting caught. A little lube and some encouragement does not fix all of that so easily on a regular sized guy, let alone what MC's packing. Not only does that make it hard to believe she could do it, but I doubt she'd be doing it so easily and without any signs of discomfort. It's too fast a turn around, IMO.
Second, Maya said several times that, even if she were able to have sex with MC, she wouldn't want to film and use it because it'd make her feel like a prostitute. That's where the "fake it with dildos" plan came from, which is exactly what they do (successfully) if you aren't on the M&J path. Deciding to just do this anyway didn't ring true to me.
And lastly -- and this one is 100% personal taste -- I don't like the idea that this triad relationship they are trying has its first proper shared sexual encounter like this. Just as a reader, I think a more intimate scene would have been called for, and would have felt truer to Maya & Josy's characters too. Though I'm sure we will eventually get such a scene, I think it's cheapened a bit by this one.
