so basically what your saying is if I want to romance the daughter just check her out ?
He will only be in a relationship with 1 girl at a time. If he is currently with someone he wont start anything with another girl. Also cant have a relationship with any of them if you're romancing claire. to not romance claire, pick "how you feel" or whatever it is (dont focus on her body) whenever it comes up and you'll start the good dad path with her and be able to romance another girl.
this is for the "light" paths, not the dark ones. haven't done those but i assume its similar, a lot of the scenes are same place and time but with a different girl depending on the path. this game requires multiple playthroughs.