Short pajamas at home
Question
Is it appropriate for my wife to wear summer pajamas at home?
Answer
Shalom u’vrachah.
Modesty must be maintained even at home, even when no other people are present.
Except when there is a need to expose the body, in which case it is permitted according to the circumstances.
See the sources.
Source
Shulchan Aruch, Orach Chaim, sec. 2:
Paragraph 1
One should not put on his shirt while sitting (Tur); rather, he should take his shirt and put his head and arms into it while still lying down, so that when he gets up he will be covered.
Paragraph 2
One should not say: “Behold, I am in the innermost rooms — who sees me?” for the Holy One, blessed be He, “מְלֹא כָל הָאָרֶץ כְּבוֹדוֹ” (ישעיה ו, ג) — “the whole earth is full of His glory” (Yeshayahu 6:3).
Mishnah Berurah, sec. 2, subsec. 1
A person must conduct himself with modesty and shame before the Holy One, blessed be He, even at night and in the innermost rooms, for the whole earth is full of His glory, and darkness and light are alike before Him, blessed be He. Likewise, because of this reason, one must always be careful, when there is no necessity, not to reveal any of his flesh, even a little, of anything that is normally always covered by clothing.