Gambit (birth name Rémy Etienne LeBeau) is a Cajun mutant who is a member of the X-Men.
Gambit volume 3
X-Men volume 2
Multiple showers with Mystique (first in the shape of Foxx then in the shape of Rogue) occur during the Bizarre Love Triangle series.
In her first appearance as Foxx, she joins Gambit in the showers and tries to seduce him, but fails, causing him to have a cold shower in frustration.
This is probably from volume 2 around the 170-173 period since Gambit refers to teaching.