There is a minhag among some people in recent years to wear a raincoat under the Chuppah. What is the source of this minhag? When did this minhag start? And is there anyone who specifically says not to do it?
I have seen people wearing a coat over a kittel at an indoor wedding. When I asked, I was told that it is a matter of modesty. The chosson is not claiming an 'exalted' status that might be implied by wearing the kittel. I was not given a source for this.
I was told the coats are worn (by both chosson and kallah, in Chabad) to confuse the yetzer hara about the identity of the couple. (I have no idea if this is the real reason.)