Harry coming home late in the night after being gone on a mission for three days.
He sees Eggsy, wrapped up in Harry’s red robe and asleep on the couch.
Harry’s shoulders droop, because of course Eggsy stayed up waiting for him, and of course Harry was late. He’s seen plenty of relationships fall apart between agents on civilians, he was scared to admit that he and Eggsy might be one of them.
But then Eggsy stirs, and Harry goes to sit beside him, waiting for yelling or scolding or something.
But Eggsy just grins, “you’re home” And curls up again Harry’s chest.
I picture Harry feeling constantly guilty. Eggsy not wanting to be suspicious but you know, agent life.
Merlin coming ‘round, trying to cover for Harry but there’s only so much he can do.
Then of course Eggsy figures it out, or at least figures out where he’s going.
One day he just shows up at the mansion like, “sup bruv, got sumfing you wanna tell me?”