One of them makes a comment referencing the "fucking with demiplanes" conversation in the Tower ("well, I suppose now I can say I've fucked on a demiplane, if nothing else" or similar).
That's literally it, no other requirements, but here's some suggestions to make things more fun, if you like. (By no means necessary, of course; have fun with it as you see fit!)
+Essek floating, Caleb catching him when his concentration breaks +One of them is very loud and somewhat embarrassed by it (but the demiplane also means they can be as loud as they want) +Power bottom Essek and service top Caleb
Specifics of the demiplane also don't matter unless you want them to. This is just for the pun.
Caleb/Essek on a demiplane
Caleb and Essek fuck on a demiplane.
One of them makes a comment referencing the "fucking with demiplanes" conversation in the Tower ("well, I suppose now I can say I've fucked on a demiplane, if nothing else" or similar).
That's literally it, no other requirements, but here's some suggestions to make things more fun, if you like. (By no means necessary, of course; have fun with it as you see fit!)
+Essek floating, Caleb catching him when his concentration breaks
+One of them is very loud and somewhat embarrassed by it (but the demiplane also means they can be as loud as they want)
+Power bottom Essek and service top Caleb
Specifics of the demiplane also don't matter unless you want them to. This is just for the pun.