I wish I could find it. There was on comic where there was a video store clerk that the main character was crushing on. She disappeared for a while, and when she was reintroduced she'd gotten into bodybuilding.
The artist drew a few cute scenes with her, including tearing the back of her dress. I think it might've been Krakow?
Failing that, Spinnerette has some decent muscles :p I'll have to dig those out to post later