The last time Mark was over Tony felt funny inside and realized he was a little excited. Mark kind of felt this and flirted with him. The funny thing is that this time Mark is just knocking on the door and Tony has a hard-on.
In fact, it was the very smell of Gus that excited me more than anything. The rich aroma of manly sweat that literally oozed out of him - not least of all in bed. It was under his arms that the smell was most intense. Trapped by those thick, dark, curly hairs.