The cheating/escorting thing was brought up but there is an option to repair things with Laura and rebuild a happy home so that kinda put a stop to those theories given the lack of other blokes touching the love interests.
Drugs came about due to her being tired a lot and/or cabbaging out.
I trust Chelsea on the basis of what we've heard so far.
She had the crush on the MC when they were younger, she told Laura and then Laura went and "stole" him without telling him about Chelsea.
She stayed with her husband despite the marriage failing until it got too much and she didn't try anything with the MC while he was still with Laura.
Now, it could be that she has an ulterior motive but I can't see what that might be yet. He's already split from Laura and she's had a thing for him for years so as it stands I think she's being genuine.
I could be completely wrong and missed something or something may happen in the future, it's still early days in the game yet.
I don't know if the chance to mend things with Laura excludes her cheating/hooking, I mean people try to reconcile with cheating partners all the time. I kinda feel like cheating seems rather likely no matter if it is escorting/hooking/being a baby girl to some rich dude. She does mention that she has some sort of a job and makes money, of course that CAN be a lie but if she lies about making money it raises some concerns. Laura mentions her needing a certain amount to cover part of the expenses for keeping Chloe and her comfortable. If she is doing drugs, she would be losing money and likely need MORE money than what MC gave her, so to me that suggests that she is not ONLY doing drugs but is cheating in one way or another. She is most likely making money somehow.
She could still be doing drugs but if the only hint for this is her being tired then I doubt it, her having been a solo parent for the last 2 months and keeping a "job" of some sort is fairly normal for parents, plus all the stress about money and husband in rehab.
As for Chelsea I just worry that this is in the end a porn game and that there will be some fetish stuff thrown at her character, I gotta say I like how vanilla she seems, I like that it is romance but I feel like something will be thrown her way to "spice it up". Her friend the receptionist is to me a hint at this, I think the most obvious thing is a possible threesome in the future. I also see the possibility of lesbian interactions between them or an option to have an open relationship.
This is of course based on two things, the fact that it is a porn game which makes me slightly skeptical of Chelseas future and it is based on the very short sequence with receptionist taking a pic of Chelseas ass. That said it is COMPLETELY possible that the kink for Chelsea is pregnancy, which seems likely and would be great imo. But I think the dev put the receptionist scene there for a reason.