'Teen Mom 2' Star Jeremy Calvert Insists He Didn't Pee on Homeless Man

"Teen Mom 2" star Jeremy Calvert says a video appearing to show him pissing on a homeless person was just a piss-poor attempt at humor ... because he claims there was not any pee or homeless person involved.

Jeremy, Leah Messer's ex-husband, tells TMZ ... he is just pretending to pee in the vid ... over a pile of trash that happened to look like a person lying on the ground, and it was all one big joke.

The video, which was shot in San Diego, caused a furor Monday on social media ... and you can see Jeremy was having a great time yukking it up in front of the camera.

But, Jeremy says all the pissing and moaning over the video is unwarranted ... 'cause the whole thing was fake.

In case you don't remember, Jeremy and Leah were hitched from 2012 to 2015 and they have a 5-year-old daughter together.