One trick pony

A prostitute who can only do one position.

Dave: was the prostitute any good?

Carl: nah, she was a one trick pony.

Emo

Hi real emo here to clear things up. noun- 1) Emo (or Emocore) is a genre of music deriving from Washington DC, and is parented by the punk movement. 2) Someone who is a fan or admirer of emo music.

Adjective- 1) relating to emo music

But since this is also Urban dictionary and I myself am an irl emo, noun- 1) emotional self-harming bitch
2) depressed darkly clothed teenager

Adjective- 1) depressed and emotional

I am emo.
I am an emo.
Because of the melodic structure and emotionally centered lyrics, P!ATD used to be emo.
Brian is an emo jackoff.