His kid finishes, and Alex kisses him lightly. Holds him for a moment longer than leans down to the floor. Unwittingly, this likely would make it clear that Alex isn't physically interested in reciprocation.

He comes up with Neil's abandoned underwear, and uses the material to clean him up. It's another thing Alex has never done, but he does it nearly without thinking anyway. Neil wouldn't be comfortable if Alex left him as is, and this had become something for Neil, hadn't it? A selfless act of love instead of shared pleasure or self-satisfaction. It's unheard of--at least, from Alex.

He drops the cloth back down to the ground, and pulls the light sheet up as Alex, for the moment, settles back in his original position--on his side facing Neil. He kisses his shoulder. "...I missed you," he admits, something quiet in the confession.