My brother has been struggling with some kind of medical issue causing him to suffer from constant boners! Mom has been taking samples to send to our aunt, the family doctor, but she won't be home in time to collect the samples we need today, so she asked me to help out. I think I deserve something in return, though - my fetish is assjobs, so I give bro an assjob instead of the handjobs mom has been giving him, and teach him how to dominate me while I do, spanking my ass and taking control. We forgot to collect the sample, though - oops! - and bro came all over my arse!!