A convenient thing with sorceresses: their appearances never change. Lambert wasn't looking too closely at who he grabbed, so long as they fit his mental criteria of 'been standing in the same spot too long' and 'looks fun to harass,' so when he realizes exactly who it is he's gotten ahold off, he scowls.

"Good thing I'm not wearing it for you then, isn't it?" His hand reaches up to adjust the way the hat tilts on his head, a little self-consciously. People have been making fun of it all night, sure, but given who it's coming from. Also, he's already unconsciously glancing over her shoulder. Where Yennefer is around, surely Geralt can't be far behind.