The term Muddy Helmet is used in reference to a film residue, coating, paste, or chunks of shit remaining on the head or just below the head of a cock after anal sex.

This phenomenon results from pounding an anus not fully cleaned of feces.

The term is often used when speaking of homosexual sex.

A muddy helmet is sometimes referred to as a "fag fuck cock collar" or a "shit kiss".

Arbitrary (and usually incorrect) units of measurement used mostly by males. Derives from men overestimating their penis size. Dick inches are much shorter than actual inches. Hence a guy can claim to have a 9 inch penis when it is actually closer to 5-6 inches. The term "dick inches" is usually used when over-estimating non-penis measurements.

a slightly less (or more) dick way of saying "no fucking way."

You meant to search porn but you made a typo and searched porm on google. You saw this on urbandictionary and it made you curious so you clicked this. now you are here.

Autofellatio is the act of oral stimulation of one's own penis as a form of masturbation. While few human males are sufficiently well-endowed and/or flexible enough to perform the frontbend required, increased flexibility achieved via gravity-assisted positions, and physical training such as gymnastics, contortion or yoga may make it possible for some. Fewer than 1% of men can successfully suck or lick their own penises.

A manipulating dick who does whatever it takes to benefit him, regardless of who he screws over. They will screw over anyone and everyone as long they get what they want.

The opposite of a chick magnet.

Used to refer to anything or anyone who easily attracts guys. Also used with straight guys who easily attract gay guys (My personal favorite).