For the mobile users

The title sums it up really. My coworker (let’s just call him Frotan) goes and takes dumps maybe 4 times a day at work. The toilet is not near my desk per se, but when he farts wetly and squirts shit in the toilet you can hear it very audibly through the wall. This doesn’t happen for anyone else - just him. I’ve been in the bathroom at the same time before and his turds are atomic blasts. The problem is whenever I have clients in the office or just in the phone they can hear every single bowel movement and splutter of his anal lips and it’s really affecting my moral at work. Each time after he’s splurted, he’ll come back looking all smug and satisfied like he know that everyone could hear him. Not sure what to do about this but just wanted to get it off my chest!