What is unrealistic to me at least isn't the fact they are interested in him. But How literally all of them are interested in him when it has only been 1 day. With that limited amount of time they got to spend with one another I think it's unrealistic for all of them to be interested that quickly. I think be more realistic if only maybe 1 of them was interested right away.( not counting the childhood friend) Sure it's not impossible all of them could be interested that quick but I think be highly unlikely. But with how slow the pacing is in this game it needs some porn logic to make them all want the MC right away.
Mia is in love with MC before anybody gets on the train.
Bree starts heavily flirting with MC when he comes over to speak with them, then also in the car ride. Sophie sees this and goes into mama bear mode since her friend has been used by guys before then tossed aside, but then she later finds out that not only is MC good looking but also a nice guy. I'm curious if her time in the pool with him is due to her being interested in him sexually/romantically or if she's still trying to protect a still-fragile Bree by diverting his attention. There might be some competitive aspect to her wanting to prove she can get the same guy Bree is after, since perhaps Bree gets more attention being more outgoing, a redhead, athletic, etc. vs the more reserved Sophie. This is a dynamic I find most intriguing.
Eve is aloof but when she spends time with MC finds out that he's not so bad if he gives her space and respect. She is sexually curious but the "I hate everything" vibe she's carefully cultured to protect her from her home environment and to act as an emotional shield has prevented her from indulging in experimentation. It's a flip on the emo/goth girl being the neighborhood slut as a way of rebelling; it's interesting that she knows less about sex than "innocent" Mia.
Ms. Hill is a standard repressed wanna-be cougar. Her sister is a fully-actualized cougar.
Jenni is a slut (or "sexually empowered woman" if you prefer) looking for a hot guy to bang. I think the whole strip club segment was throwing a bone to the boners out there looking for something to whack off to.
For me the only thing other that's really out of place with the art camp group is the shed scene with Bree confessing her preferred fetish, as that seems to have cropped up way too early. It might be that Bree is prone to getting involved sexually with guys faster than she is emotionally prepared for, and we are seeing that happen when she's separated from her protector Sophie, but telling MC how she wants him to do her is a little TMI at this level of their relationship.
