鱼水之欢

魚水之歡
yúshuǐzhīhuān
  1. the pleasure of close intimacy in a couple (idiom)
  2. sexual intercourse

CEDICT

  1. (euphemistic, figurative) the pleasure of close intimacy between a couple; (the pleasure of) sexual intercourse; harmonious and joyous life of a married couple
  2. the pleasure of close intimacy between a couple; (the pleasure of) sexual intercourse; harmonious and joyous life of a married couple

Wiktionary

比喻夫妇好合，和乐融融。

重編國語辭典

Entry Composition

1 鱼水 yúshuǐ fish and water (metaphor for an intimate relationship or inseparability)
2 之 zhī
  1. (possessive particle, literary equivalent of 的 de)
  2. him
  3. her
  4. it
=3 欢 huān variant of 欢 huān
=3 欢 huān
  1. joyous
  2. happy
  3. pleased
=3 欢 huān
  1. hubbub
  2. clamor
  3. variant of 欢 huān
=3 欢 huān
  1. a breed of horse
  2. variant of 欢 huān

Related entries

性交 xìngjiāo sexual intercourse
我性交的时候会出血。

I bleed when I make love.

Source: Tatoeba

性媾 xìnggòu sexual intercourse
房事 fángshì
  1. sexual intercourse
  2. to make love
床笫之事 chuángzǐzhīshì
  1. bedroom matters
  2. sexual intercourse
人道 réndào
  1. human sympathy
  2. humanitarianism
  3. humane
  4. the "human way", one of the stages in the cycle of reincarnation (Buddhism)
  5. sexual intercourse