And that's the reason why Iris is persistent to take Millie to her apartment, She is worried that Raymond trying to do something to her.
So, go for the SFW route until her birthday scene ;]
I see. You do what you wanna do, but I personally would either just make her at least 18 right off the bat or not give us any naughty scenes until her birthday comes, cause it's kinda weird that we have the option in the first place, not gonna lie. Aside from that frankly major overlook, the game is pretty good