Being like 100% sarcastic here cause I had to see 2 horny threads today lol!
I hope the sex isn't done too often because I enjoy it being something you build up to and cherish. Although I know Larian said that some of these characters are non-monogamous and we're all adults... alone... together... I want to get to know my party better with something other than my body.
I'm perfectly fine with fade-to-black. I'm perfectly fine with not-fade-to-black. But I will always and forever prefer a meaningful, satisfying slow burn. I'm even okay with it if its an emotional slow burn with a character who goes from just wanting sex to real love. (Morrigan in DA:O was a great example of this. I love that goth chick.)
I get that non-monogamous people are a thing but I do not think non-monogamy = mature relationships. (It can, but is not an exclusive definition)
I'm hoping player choice has an influence on the shapes the relationships can take. Through dialogue players who want that sort of thing can have friends-with-benefits relationships. But for those of us who actually enjoy monogamy (10 years of marriage and going strong) I hope we can have decent relationships with the characters who have non-traditional world views. I.e. Astarion is fun and stupid sexy while Gale seems really nice but he also doesn't do it for me. Shadowheart seems promising and I'll definitely romance her but I want a good male option too.