I thought it was gonna end with an announcement that the model was pregnant due to the semen floating around in the bathtub, and it being some sensational virgin birth. Not actually quite sure that would be possible IRL, but eh, hentai logic.
Assuming that male protagonist is the director of what appears to be a gravure photo-shoot, if not a softcore AV, I give him max credit for adhering to the policy not to do "this and that" (or anything close to it) to the models. Not that he needs to, with the make-up girl (or more precise, make-up woman) being there for him, when he needs to (*cough-cough*) "release". And make-up woman seemed to enjoy it, too.
Conclusion: It's Good To Be The Director ... lucky bastard (GRR).
Hmm, around the beginning, I expected the model being filmed to be the one to get some action, but the moment the makeup artist went in...Well, that's perfectly fine too.
Although I must say I did kinda hope she would at least get some action too.
Great ending though! So...Japanese style inn sequel, maybe?
... mayhap, did this girl become... oh, I dunno, a Makeup artist?
Maybe you ended up living with her? Mmm?