She found her brother’s girlfriend wiping strands of cum from her face.

“You know that’s an urban myth, about spunk being a cure for acne.”

She sees the girlfriend is about to cry

“I’ll show you the proper cure.”

She takes the girl into her bedroom and tells her to lie on the bed.  With her skirt hiked up and knickers pulled down, she straddles the girlfriend’s face and rides her hard and fast.

Once she’s orgasmed, she climbs off again.

"Of course, one application isn’t enough so you’ll need to call around again tomorrow, yeah?"

The girl nods eagerly.