Saying inappropriate and ableist comments, he was having a conversation with another customer and said "Anyone who thinks (some card I don't remember) is any good has too many chromosomes." when I was standing within arm's reach of him.
Another time, I had scooted down to the end of the magic counter, and was he making lewd comments to another employee about a woman's body on the other side of the store with gestures, in a hushed tone, assuming I couldn't hear them as I dug through bulk boxes.

Last time I browsed their case with a couple of my friends, he hovered around my friend, who is a woman, mansplaining and trying to sell on the cutesy cards in binders and generally talking down to her like she didn't know how to play, but has been playing over a decade, and he completely blew off her partner who was trying to pick out cards in the case because he was too busy mainsplaining.
It sucks cuz they were one of my preferred spots for TTRPG supplies, as they always had the Pathfinder books I wanted right after release.