I'm not sure where this notion got started - probably a late nite comic - but chaps are by definition 'buttless.' Do a Google image search or heed the peerless Wikipedia:

"sturdy coverings for the legs consisting of leggings and a belt. They are buckled on over trousers with the chaps' integrated belt, but unlike trousers they have no seat and are not joined at the crotch." 

We noe return you to your regularly scheduled program. 

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken