Farrah Abraham Bares Ass, Goes Topless for Nude Fashion Label Shoot

Farrah Abraham's got down and dirty for her latest fashion photo shoot ... leaving little to the imagination.

The former 'Teen Mom' and 'Backdoor Teen Mom' star went all out by showing off her bare backside and front side in a series of racy pics for the fashion label, PrettyLittleThing.

Check it out -- Farrah's rocking several different looks ... all of them very naked.

It's hard to pick a favorite among the provocative shots ... but riding a sheep-shaped shrub without any sort of saddle underneath is definitely Farrah's most risqué (and risky).

Gotta admire her courage.