two pennies' worth

all one's life's worth

A momentous matter; a very serious risk; a difficult task or situation.

beast with two backs

Two people united in sexual intercourse in the missionary position.

dime's worth

An insignificant amount

eat for two

To be pregnant

fall between two stools

To fit into neither of two categories and, hence, be neglected or fail.

feed two birds with one scone

Synonym of kill two birds with one stone.

for two pins

Readily, with only the slightest encouragement.

greater of two evils

The most harmful or unpleasant of two undesirable alternatives.