A foul joke/prank performed. While perturbed, you take a dump inside a laundry machine dryer thats filled with your white laundry. You then run the dryer to 'mix the cement' and leave hardened skid marks on the victim's wardrobe.

A sex move, especially popular in the south, where a girl holds a mouthful of hot grits in her mouth while performing oral sex on a guy.

A foul, disgusting, horrible, drink made of a shot of lime juice and another shot of Bailey's Irish Cream.

You drink the lime juice first and hold it in your mouth. You then shot the Bailey's and swish them together in your mouth as though you were using mouthwash.

Within several seconds your mouth will be full of a rancidly textured ball of goop (the "cement"). As a straight male I can't vouch for it but it must be similar to having a mouthful of cum. Swallowing it is even worse.

They are so gross that the clown who buys you one of these is lucky if you don't gob it back in his face.

Better choices can be found in the tags below.

an alcoholic drink;
a mixture of lime juice, vodka and bailey's;
when swished inside one's mouth forms a solid texture that is similar to cement mixture;

In baseball, when a pitcher throws a slider that doesn't break and hangs in the trike zone. It becomes an easily hitable pitch.

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.

Grabbing a male's genitals and squeezing, twisting, and pulling them. Once someone has successfully completed a cement mixer, that person must yell the words 'CEMENT MIXER'.

Performing anal sex while the recipient releases diarrhea in a slow, controlled fashion that is timed with each thrust. Traditionally, the partners work together to mix the diarrheal substance into a thick paste, although recipients often allow for the occasional explosion of liquid stool for added flair. Additionally, if the right consistency is attained, the diarrhea acts as a very effective lubricant that is safe for use with most latex condoms. Can easily transition into other maneuvers, such as a Dirty Sanchez or Hot Carl.