Reason why I brought up similarity between Ian/Cindy/Axel and /LenaMike/Ivy. Mike and Lena's relation might not be exact same but he's still a love interest for Lena with a proper romance route too and Lena isn't a NPC, she's a MC. so if Mike can fuck Ivy regardless of our choices in that route, why do you think Ian is going to be any special?
Anyways, tbh I don't care whether Cindy cheats on Ian or not, I mostly treat Ian as NPC in my playthrough, so no big deal for me. I just felt Cindy cheating with Axel is going to be one of those events in the game that happens regardless of our choices hence my comment.
Why do I think Cindy won't cheat on Ian like Mike did?
Like I said, because Cindy actively displays interest in her relationship with Ian. She is unhappy when Ian sleeps around, she keeps trying to reassure Ian that she will dump Wade for him, she has a deeper relationship with Ian than Mike has with Lena.
Mike never committed to dumping his girlfriend for Lena, Mike does not have a deep relationship with Lena, Mike does not care about who Lena sleeps with.
With those differences in mind it would make as much sense to say Alison or Holly would cheat on Ian on the pure romantic paths, only because Mike did so on Lena's path. Even though the situation clearly have meaningful differences.
Cindy has displayed way too much affection for Ian than Mike ever showed for Lena. It might still happen, but if it does it would be pretty bad writing, whereas Mike situation was just consistent with his character.