Disclaimer: Still not mine.
When Grantaire firsts ask to paint him for a project in his Study of the Human Form class, Enjolras hesitates. He knows that a painting is a huge time commitment, and he doesn't know if he can give up that much time when he could be working. When Grantaire asks again when Enjolras is tipsy on lemonade that Bahorel spiked, he says yes.
When the day arrives and Grantaire shows him what he has sketched ahead of time for the painting, Enjolras drops his bottle of water. "Look, 'Taire, I know we've talked about this before, I'm asexual, this could never…I don't…I'm not…"
Grantaire snorts and rolls his eyes. "I don't want to fuck you, E, I just want to paint you." Unable to produce a counterargument, Enjolras shuts up and starts to undress as Grantaire, suddenly taking on a grace that he typically misplaces, starts working on the background.