A Silkworm
A silkworm is a guy who can't get it up unless he's wearing a bra, and even then he probably just pees on it.
My uncle is a silkworm. He wears his sister's bra to get hard.
That guy at the gym is a silkworm. He can't lift a weight without a bra.
My brother is a silkworm. He peed on his girlfriend's bra last night.