And she found atomic spectroscopy boring.
I wouldn't COITUS her with your genitals.
The Big Bang Theory Season 9, Episode 8
So it went beyond the mere fact
of COITUS to a blow-by-blow, as it were.
The Big Bang Theory Season 4, Episode 20
And then after dinner,
we will have birthday COITUS.
The Big Bang Theory Season 11, Episode 11
...if we should actually engage in COITUS
at least one time in our relationship.
The Big Bang Theory Season 4, Episode 5
Frequent COITUS dramatically increases
the odds of fertilization.
The Big Bang Theory Season 1, Episode 15