"Well.." It was important to create anticipation, so he drew that out as long as he could while he settled in closer-- let Alex feel like he was being the big man in this situation, a false sense of security for when Henry pressed him up against a door or a while.. they must be drawing closer to Alex's domicile somehow, which means then his plan could be enacted.

"I have thought you were rather the most attractive man I've ever met at the Peace Conference, and then when the spreads of you in People, well.. that is when I imagined ah.. shagging you."

Ah look how cute and british he was, Alex... he said 'shag'