bǐ yì shuāng fēi
lit. a pair of birds flying close together (idiom)
fig. two hearts beating as one
name of a sweet and sour chicken wing dish
shuāng sù shuāng fēi
lit. to rest and fly together (idiom)
fig. to live in each other's pockets
to be inseparable
shuāng fēi
flying in pairs
close union as husband and wife
round-trip flight
(slang) threesome