Farrah Abraham has finally been opening up about that sex tape professional porn she did with XXX star James Deen. You know, the one she pretended to not know about until he inadvertently sabotaged her plans.

Now Deen has removed the (love) gloves and is firing back at her allegations that his naughty bits weren't up to snuff.

A TMZ photog texted Deen to ask about Farrah's low blow, to which he responded:

What is her problem???? It is obviously medium sized"

Why Farrah would make a claim like that when a cursory Google search provides quick and easy evidence to the contrary is beyond explanation. (No, we won't link you to that. Go find it yourself, perv.)

You'd also think she would make sure to personally approve someone's manhood before deciding to do the dirty with him on film. But Farrah's mind works in mysterious ways.

At any rate, Deen isn't too worried about it, adding:

On the list of things I care about the size of my penis is number 783."

Since Farrah wants a couple million bucks for the footage and Deen would be entitled to a large cut, we're guessing that probably ranks higher on his list.