One of the funniest things about AC for me is that literally everyone fucks. You'd be hard-pressed to find a character that is without a doubt a virgin. It's not even implied, simply the truth.
Pretty much all of the protagonists have descendants, AKA have had children, AKA fucked. And even those that haven't have had romances in which they fucked.
Altaïr, Ezio, Edward, Haytham, Connor - ancestors of Desmond, we know of and a little bit about their children. (Or a whole game's worth for each Kenway)
Shay? He has a grandson and later descendants, according to the books. Arno? The 2016 movie showed him as being in Michael Fassbender's family tree. (Also, as funny as it is to think that he and Elíse didn't do anything frisky, they are French.) Jacob had Lydia, Aveline had a grandson and is the ancestor of Subject 1, Adélawé has a surprising number of documented descendants.
On the RPG side of things, Aya and Bayek had a kid, Eivor, Kassandra, Yasuke and Naoe had romances with NPCs.
The only protagonists that don't have confirmed children are Evie and Basim, but even that is debatable. Do Loki's children count as Basim's? Did Evie and Henry have a kid? And even if they didn't, it's likely they consummated their marriage given the time period and their respective cultures.
The side characters aren't entirely safe from this: Malik, Claudia, Machiavelli, Yusuf, Shao Jun, Achilles and many, MANY others have kids according to the books and the 2016 movie.
Ironically, the modern day cast are the outliers. Sure, there's Bill, Desmond himself, if you wanna go by the comics, and I think Shaun and Rebecca were implied to be expecting in Valhalla, but beyond that? Virgins. It's mostly a result of the characters post-AC3 being dryer than the sun, so we don't know much about them. And yeah, they are adults in the 21st century. They will likely get some, but we're running on pure facts here, not assumptions!
This is not a crazy thing to notice for such a huge franchise, especially considering that the plot early on relied on this to keep going, but it's funny in retrospect. Most of the characters in Assassin's Creed range from "in theory, probably did it at some point" (Evie) to "certified slut" (Ezio)
