I always wondered if when demigod's travel in their sleep for the plot reason stuff, if they ever wandered to the wrong place by accident. What if all of the gay content happens through set ups, and when Percy goes to sleep, he can see what's happening elsewhere. You leave a clue so that Will can find Nico at night, and then see what happens from you saying that. Tell Conner that a magic item will be left unattended somewhere, and let an Ares kid know a thief is coming, so he gets caught. I personally like the idea of setting up that kind of stuff to happen, even if I have no particular interest to actually watch it.
Basically, a chance to see non protag sex. Always wondered about that in adult games, always seems like only the protagonist has sex, unless the game specifically is about the protagonist being the one not having sex. Imagine the night before the Argo 2 goes to the final battle. You play Leo, and peep on all the other happy couples. Not having to try and break anyone up, or be the one to get with all the girls, let the people enjoy their own relationships. (or maybe find out that Leo has a hologram of Calypso, in a strategically placed area with a convenient exhaust port in the furnace of the ship)