Uh ... we aren't wearing this to our kids' music classes! But then our abs don't look like Kourtney's!

Kourt flaunted her rock-hard abs in a sexy crop top and sweatpants on Tuesday, as she took son Mason to his afternoon class. Is she doing it to tease Scott? Or hell -- maybe after working hard on that sports court at her house with her sisters and her trainer, she just wants to show off the fruits of her labor. Well more power to ya, Kourtney!