It's Well Hidden
I just asked Wesley to help me lift a table up on my kitchen table so I could paint it. I wasn't really expecting much in the way of actual help, but he was standing there and if nothing else, I figured he could help steady it in the air.
Turned out he was stronger than he looked and that was exactly what I told him -- something like, "Wow, Wes-man, you keep your muscles well hidden."
His reply, "My skin is so tight they just can't pop out."