Enjolras has never seen Grantaire dancing, because he has his own work to do -- he is the conductor. But he knows Grantaire does really well from the audience's reaction.
At every curtain call, Grantaire chooses Enjolras' hand to hold. Standing so close to the leading dancer, Enjolras feels himself evoked. Heat radiates from Grantaire's body while he breathes heavily due to the performance and excitement. Each time, Grantaire pushes Enjolras forward to gain the praises from the audience. Enjolras could hear R's applause at his back. Grantaire always looks gorgeous at curtain calls. His hair is wet, sweat on his face mixing with the glam makeup.
This makes Enjolras so frustrated not able to watch Grantaire dance. He only has several glimpses of glance to give when he is turning pages.
On the contrary, Grantaire could always hear Enjolras. Actually, he dances on Enjolras heartbeats. They cooperate heavenly, like they are meant to be. Enjolras always knows his emotion needs. He is forever easily with Enjolras at every beat, every pause, every up, and every down.
Grantaire loves Enjolras.
So, one day, after he was drunk enough, he entered the orchestra pit just before the theatre is about to close. He encountered Enjolras with a violin in his hand and music score book in front of him. Grantaire stumbled to Enjolras because he thought the rough image of Apollo was from his illusion.
He is a ballet dancer, of course he appreciates beauty and strength. And Enjolras is a model of beauty and strength.
Illusion Enjolras looked at him and frowned .
"You have a performance tomorrow night."
"That's exactly why I'm drunk, Apollo."
Enjolras said something about not being Apollo but Grantaire did not bother to listen. He leaned in, until he was merely an inch from Enj's lips.
"Play something, please."
Illusion Enjolras followed his instruction easily.
Then he danced, with the music.
If an on-stage Grantaire is a treasure, then a drunk Grantaire dancing is purely a bliss. Grantaire kissed his Apollo afterwards. Enjolras fucked him in the orchestra pit.