Because Harry let no one in. Harry was been in Kingsman for decades and didn't have the time and space for anything except Kingsman in his life. Not a partner who might ask questions or be a weakness.

Harry didn't say any of that, of course. He pushed his face into Eggsy more, shielding his eye from the little light there was and sleeping on for a while. The medication was working to unknot his migraine and stop him waking up from the nausea.