Enjolras always makes sure he looks his best for meetings, he want a to help make Les Amis look as professional as possible.
This of course means that Grantaire had never seen him without the extra level of preparation. They only ever saw each other at or after meetings.
And this of course means that the first time Grantaire sees enjolras with stubble, bed head and rumpled teeshirts and pajama pants after planing a rally for 4 days straight he legitimately can’t can handle it. Its to much. He doesn’t always come with freshly pressed button downs??? His hair isn’t always perfect????
He ends up spending the better part of their movie night staring at enjolras and wondering how on earth he thought this man could always be put together when he was so clearly more comfortable in a t shirt than he would ever be in a suit.
And how on earth he was equally attracted to both.