Personally, before D's final corruption, I would like to see F and D have an impromptu dry hump (clothed) to orgasm in a park, or some place like that. Later, during a naked massage, when she is sitting on top, he massages her bottom and she begins slowly grinding against him and they begin the experimental rubbing of their genitalia which recreates the park (?) experience; only a lot more intimate. Next, with her initiating it and sitting on top (cowgirl style then maybe reverse cowgirl) and shyly holding hands with him, then later with him initiating it as he crawls out of the shower and into bed with her; moving up between her legs (gentle missionary grinding action). Keeping in mind that kissing her lips and nipples during this makes her lose control easier...this can also be repeated in the tub, in bed while trying to sleep with MC behind her and his cock between her legs rather than against her back, and on the sly with E nearby. By this time she should be screaming (in her head) for the final plunge.
I also think that D and E might ought to get a bit drunk and playfully tease each with a little mild lesbian action without D losing her virginity. It could lead up to a less awkward threesome with MC.
However, more than that, I would like to see D and Georgina have a mild lesbian scene during a photoshoot; without knowing MC is present. She could also, in guilt, reveal it to him shortly afterward. He could reassure her that he knew, but didn't want to stop such a tender moment.