Naturally Sam didn't mind undressing in front of Louise at all, at least not under normal circumstances. He wouldn't have minded in a shop changing room either, so long as they replaced the charm so nobody could accidentally walk in. No, it was what the undressing was likely to lead to that he refused to think of while they were in public. After all, they were both professors now and it would be horribly embarrassing to read about "Professors caught misbehaving together in shop changing room". He could just imagine the look on Minerva's face...
For a moment it seemed as if Louise was actually planning to stay in the changing room though, but then at the last minute he was saved by either the shop owner or the elderly couple, who had apparently realised she was also in there. "We must remember to use a sound cancelling charm next time" he whispered as she left.
As he wriggled out of the tight trousers and hung them over a peg on the wall he heard Louise talking to the shop assistant. "I can still hear you, you know!" he called as he pulled on the lighter pair. Already he could tell these were better - more comfortable, fitting better and, as he fastened the buttons, they were actually more flattering than he'd imagined. He actually stood in front of the mirror for a moment, then swapped the brighter waistcoat for the one he'd tried on first. Yes, that actually looked quite nice, he decided. Sam pulled the curtain back, the brighter waistcoat still over one arm.
"Who says I can't put an outfit together for myself?" he asked, though it was quite true that Louise had actually picked out most of the items for him "I don't think I need to try the other trousers, these ones are comfortable and they look fine with the first waistcoat..." Sam grinned. It was so far away from his usual style he thought vaguely that he should feel self-conscious, but actually he felt rather fine, particularly given how Louise was dressed. Then he noticed how she was looking at him and he did feel a little shy. He covered the feeling by grabbing the trousers he hadn't tried on and holding them in front of himself. "You don't prefer these?" he asked, hoping she would say no "I'm happy with what I've got on...and I'm having this as well!" he added, gesturing to the second waistcoat.
This part had actually been fun, but now Sam was eager to pay so they could get out and explore the rest of the stalls and entertainments.