Two dwarfs go into a bar, where they pick up two 'working girls' and take them to their separate hotel rooms. The first dwarf, however, is unable to get an erection. His depression is made worse by the fact that, from the next room, he hears his friend shouting cries of..
'Here I come again! ONE, TWO, THREE, UGH..... Here I come again! ONE, TWO, THREE, UGH!'
This went on all night long.
In the morning, the second dwarf asks the first, 'How did it go?'
The first mutters, 'It was embarrassing. I couldn't get an erection.'
The second dwarf shook his head.  'You think that's embarrassing? I couldn't even get on the bed."