The Hannah Montana star bought her boyfriend Liam Hemsworth the penis cake – which was big enough to make any man feel inadequate, mind – for his birthday … and then she proceeded to, erm, fellate it.

We bet Hemsworth’s publicists are not too chuffed about the photos either, since he’s about to make waves in Hollywood for his role as Gale in The Hunger Games.

The cake, a massive phallic confection, was rolled out Saturday night at Club Icon in Downtown LA, and Miley Cyrus, 19, quickly jumped at the photo opportunity.

We wonder who blew … the candles?

Click here to see the photos