Andrew needed that, needed Jack to lay his fears about their relationship (platonic and romantic) to rest and bury them under the ground that had been laid down by his perma-arguing parents.
He needed Jack this close to him as well though, close enough that it was easy for him to put his hand over Jack's on his face and lean in to kiss at that grin, take it in and make it a part of himself and beg Jack without words, promise promise promise.