Jack knew he had a fair point, so he reached down and began undoing his own jeans, sliding them down and off. He kicked them to floor and then removed his own shirt. Normally he wouldn't be self conscious about his appearance, but he really wanted Mac to like what he saw. So, for the split second he waited for Mac's response he was very nervous, but he did his level best to hide that fact from the young man beneath him.
Finally he couldn't wait any longer, his face flushed slightly and he started to look away. He couldn't hide his nerves anymore, and there was this nagging though in the back of his mind that Mac wasn't happy with what he saw.