Yeah I think if there is going to be unavoidable cheating it won't be with Chris TBH Anna seems fully aware of what a scumbag he is if you choose the top choices. He is stuck in the friend zone and is actually kind of pathetic when you think about it.
If David is forthecoming about his dads companies problems then mr Grant wont be able to use that to blindside Anna into fucking him for money (it will still be tempting I'm sure but she won't be emotional because it won't come out of the blue).
Marvin has no chance. Fat boss Anna hates heh as no chance unless she goes full slut and again David doesn't tell her about the company.
I think the only one Anna might fuck or fool around with irregardless of choice will be Jake. He is the one that so far whatever you choose she is still attracted to and thinks about and he doesnt have the air of suspicion about him. Now again depending on # of routes she might just makeout/blow him rather than fuck him if David doesn't cheat/is forthecoming about gym girl/warns her about Jake without coming across as a jealous bitch and then they can reconcile after.
I don't agree with people who say David is a bad husband though. Anna is hypersexual right now but they had just gone through a dry spell and a baby so his libido is already turned down and then he has super life altering stress right now he couldn't and she shouldn't expect him to just drop that and come home and fuck her. When your in a long term relationship you gotta make an effort to meet your partners needs but you gotta meet your own also doesn't make you a bad partner. My Fiancee and I are both Physicians and during residency when we were working 16 hour days and come home tired and stressed as fuuuucckkk our solution to the other one being horny after we worked a long shift was "yes you can fuck me while I'm sleeping - just don't wake me up"