There is a custom that I have seen at weddings that the couple holds hands after the chupa to the yichud room, is there a problem of showing public affection? Is there a problem outside of a wedding for a husband and wife to hold hands in public? Does the shulchan aruch hold public affection is assur?
There is no prohibition in holding hands after the chupah. Some prefer not to hold hands, in particular — but no only — among Chassidic communities, as part of the general custom of avoiding public shows of affection. Many, however, make an exception to this rule for the chassan and kallah (for holding hands), and the practice has become customary for many. Some cite the Torah’s wording concerning Yitzchak, who “brought Rivka into the tent of his mother Sarah,” as a possible source for the custom.
In general, public shows of affection are improper, and should be avoided, included holding hands.
Concerning holding hands after the chupah: see Otzar Haposkim, 55:1:19.
Concerning general shows of public affection: see Rema, Even Ha’ezer 21:5;
Kitzur Shulchan Aruch 152:11 (public shows of affection are wrong because they can bring people to improper thoughts); Shaarei Rachamim 25:6; Minhagei Anshei Hatorah (chap. 3) (concerning calling one’s wife by affectionate names in public).