when you put gravel(large gravel, like 2B size gravel) into a girls butt and then proceed to have sex and cum in her butt. after cumming the girls swishes the gravel and semen mix and shits it out onto the floor where you are waiting with a trowel to mold it into whatever you so choose, preferably a yert.
"Wow, he sure gave her a great cement mixer last night! Just look at the size of the yert they made!"
9👍 11👎