yuān yāng xì shuǐ
lit. mandarin ducks playing in the water
fig. to make love
鸳
yuān
mandarin duck
鸯
yāng
used in 鴛鴦|鸳鸯[yuan1 yang1]
戏
xì
variant of 戲|戏[xi4]
水
shuǐ
water
