This was hard to summarise in a thread title so it's probably confusing. I have two protagonists in my romance who, I am hoping, the readers will want to be together. But they don't get together until roughly 1/3 of the way through the book. Before that, and indeed before the story starts, the male protagonist has a casual arrangement with another woman where they just have sex, no relationship. I'm wondering if it's a mistake to include a sex scene between them. It won't be a blow-by-blow ( ) account and it isn't gratuitous - it serves a narrative purpose, by giving the reader clues that casual-arrangement-woman is more into him than he is to her, even if male protagonist doesn't realise it, which is very important to the plot later on - but I can't help feeling it's a mistake. Especially since the couple of sex scenes between my protagonists are much softer, more romantic than hot (although I hope they're hot enough). I don't want to end up with the most erotic scene in the book being between one main character and his not-love-interest. At the same time I definitely don't want to make this one romantic because it's from my male character's POV and he has no romantic feelings towards this woman, although he likes her as a person. There's not a lot of sex in the book as a whole. I have two sex scenes between the protagonists that go into any kind of detail, because both are important to the plot, and the rest of the time it's more of a "then they went to bed" or "in the morning" kind of thing (don't worry, those are not verbatim extracts.) This is the third time I have found myself writing a sex scene between male MC and casual-arrangement-woman, which I should probably take as a clue that it should be in there. I deleted the first two attempts because I was worried about it but now I'm wondering if I should leave this one in. Obviously it's hard to comment without having read the book, but what are your initial thoughts about this? Have you read any books where this happened, and did it work for you?