At some point when u visit his house hes going to tell u that hes still a virgin at this point u have a choice ask Anna Or Sam if u ask Anna u can invite him to studio for extra content and i think thats it if u ask Sam u get more scenes, way more scenes.
As far as I know yes, at least from what I've seen when you pick Sam he can't do anything with Anna, I haven't tried the Anna route tho, so you can just save in your bedroom and try different routes
