A girl wearing a pair of pants so tight, like a camels toe, but tight enough so you can see her lips moving.
Hence "the mumble", "i can see her lips are moving, but i cant work out what she's saying".
see whispers, cameltoe

A swimmer

MUMBLER - an attractive girl in tight shorts or jeans, etc.i.e.you can see the 'lips' moving but can't quite make out what they're saying.

camel toe taco jeans When a women wears pants so tight you can see her lips move but can't hear what she is saying.

very tight trousers, as worn by exhibitionist women.

A homosexual person. Of or pertaining to a fag. Someone who does not talk straight but talks gay.

Seeing vaginal lips and outline when a girl is wearing tight trousers usually cotton or something thin