'bellcrease' or creaser in fact refers to a gay due to the creasing of the stomach muscles when bending over in order to recieve a cock up the batty. However, one may use it as general term of abuse, comparable to gaylord.
The 'bell' prefix is used simply as an indication of the tip of the male genitalia and the target's love thereof.

Bellcrease (or Bellcreaser) (noun): An insult, originally used to describe a man whose bell-end has become creased or crushed for whatever reason. Thought to have originated in County Durham, England, its use is becoming more widespread in several parts of the country.