Farrah Abraham My Sex Tape Co-Star Has a Small ...

4/14/2013 7:59 AM PDT BY TMZ STAFF

Farrah Abraham
is so pissed that James Deen blew the lid off her sex tape scheme, she went straight for the jugular when expressing her feelings about him -- and by jugular, we mean his manhood (and by manhood, we mean penis).

The "Teen Mom" star has been in a war of words with Deen ever since he told us that Farrah's "sex tape" was really just a porn shot at her request. 

Farrah took a below-the-belt shot at Deen while talking to our photog yesterday ... which is ridiculous and gross -- ridiculous because he's a male porn star (um, hello!?!?!?) and gross because her mom was standing there the whole time.