Apparently, even adults have a hard time grasping this concept. If you're going to make a sex tape, you better damn well hope you're doing it with someone who's not gonna shop it around. Maybe even marry the person before you do the dirty on camera.

Example number 5,382: Former 'Teen Mom' star Farrah Abraham.

According to a report from TMZ, the hard-partying Abraham -- one of a select few who went from knocked-up-irresponsible-teenager to celeb superstar thanks to MTV (which allegedly plays music videos?) -- is now a star in a new kind of show. It apparently involves her and a dude getting it on, and now the tape is being shopped to porn companies.

TMZ reports the tape is about 30 minutes long, is recent and is extremely, um, "visual." To add more warm fuzzies to this vomit-inducing tale, Abraham was spotted holding hands with, you guessed it, a porn star. This, of course, is raising the rumor that James Deen (a schtick porn name, who knew?) is the co-star in the video.

This comes just about a month after Abraham was busted for DUI, blowing (get it?) twice the legal limit.

Hollywood does wonders for children.