Mary-Kate's Playing Footsie With Shoe Designer Scott Campbell

Summer lovin’ and Mary-Kate Olsen is having a blast!

Star magazine reports the pint-size twin is getting “hot and heavy” with UES co-founder and shoe designer Seth Campbell.

A source told the mag: “They’ve been hooking up …. It’s just too early to say where it’s going.”

All we can say is, get it girl!

[Image via WENN.]