[Either that's a very good distraction, or he's not all that uncomfortable losing his sweatervest. Could be both, it's not like she's exposing anything to risky by removing that particular item of clothing. It does make his excitement spike a bit, all this pushing of boundaries. Undressing.
Well, if she's going to push, so is he. Carefully. Those hands of his are slipping back to her sides, caressing up along her waist and just barely brushing against the very edge of more interesting areas as he makes his way over her ribcage.]