The art of belming is to protrude your lower lip outwards by inserting your tongue between your lower teeth and lip and extending your tongue forwards so.
The clear implication of belming at someone is that either;
- You don't really believe a word they are saying.
- You think they're a MONG and not really worthy of proper conduct.
The act of belming can be enhanced in either of two ways, preferably both;
- Stroking the extended chin at the same time. The longer the strokes, the more you're infering that lies are being told.
- Saying the world 'belm' at the same time. Quite a difficult word to say clearly when your tongue is sticking your lower lip out, but effective all the same.
If a friend was to state "Yes, that Saturday evening really was fun. I had both Kate Moss and Linda Evangelista fighting to take me home" you would be quite within your rights to say "Oh, really..." while belming all the while.