My top's slippery too...

"When I get all sweaty and wet, I get so slippery, things just seem to fall off..." You shrug, tossing him a glance.

"That so?" He grins back at you.

"Oh ya, I mean," You look down at your ample cleavage, "These skimpy panties and these thin little shoulder straps are all that's standing between me and nudity at this point!" You glance at him again, "I'm serious, if you slipped them off my shoulder, bam, boobs out!" You nod.

"Oh?" He reaches up, slipping off one shoulder strap, then the bra strap, before reaching across and slipping off the others.

You toss him a grin, jostling your chest, your top slipping down, freeing your chest to the gym at large, your dark, big nipples bouncing freely as you jog along. A quick hook of your thumbs and you slip the tops likewise over the curve of your hips, letting them fall down your slippery legs.

"Told you. Veeeerrry slippery." You nod, smiling at him in nothing but panties.