Shulchan Aruch Harav Siman 639:
(See especially the last sentence of 9, and note that 10 doesn't really apply today since we no longer celebrate this way. But I included it since it's instructive.)
9) At present, people at large have adopted the practice of following
a lenient approach when it comes to sleeping [in the sukkah). Only
those who are punctilious in their observance of mitzvos sleep in the
sukkah.
There are those who have offered rationalizations for married men,
(explaining) that they are obligated to bring happiness to their wives
during the festival and women are not obligated [to observe the mitzva
of] sukkah. Hence the fact that a person does not desire to separate
from his wife is considered a matter associated with a mitzvah, and
whoever is occupied with the performance of a mitzvah is exempt from
performing a different mitzvah, as explained in sec. 640[:18]. Thus [a
married man] is not obligated to sleep in the sukkalt at night. [The
above line of thought applies] even if one's wife is not ritually
pure, for she is happy when her husband shares the privacy of their
room with her, as will be explained. Nevertheless, it is desirable
that one follow the stringent approach and have a private sukkah where
he can sleep together with his wife, and thus perform both mitzvos.
10) [The following laws apply when a man) marries a virgin bride two
or three days before the festival and thus the seven days of the
[wedding] celebrations extend into the festival. (Weddings are not
held on Sukkos itself, as stated in sec.
546.) In earlier generations, it was customary for the bride and groom to spend all seven days of the [marriage] celebrations secluded in a
private room called a chuppah. Other people would join them only at
times when they wanted to celebrate with them and eat and drink with
them.
The groom, his attendants, and all the bridal company - i.e., the men
who eat with the groom- are exempt from [the mitzvah of] the sukkah
for all seven days of the [wedding] celebrations. They are permitted
to eat, drink, and celebrate outside the sukkah, i.e., in the room
called the chuppah. One cannot celebrate properly in a sukkah, because
one can truly rejoice only in the chupppah, which is essentially where
the bride and groom dwell; it is here that are alone. The essential
dwelling place of the bride and the groom cannot be in a sukkah, for a
[typical] sukkah has only three walls and is open on the fourth side.
A groom would be embarrassed to rejoice with his bride in such a
place.
Today, therefore, when a sukkah is customarily built with four walls,
even a groom is obligated [to observe the mitzvah of] sukkah.
