Only once have I ever dressed alike in my adult life and it was not planned.
My best friend and I were shopping and we both saw a sweater we liked. Neither of us got it though. Later each of us mentioned it to our boyfriends as they were asking about Christmas gift ideas. Needless to say, we both got the sweater we liked.
A couple of days after Christmas, the four of us go out. It was really cold, so everybody was bundled up good. It wasn't until we were inside the restraunt and we undid our coats did we see that we had our sweaters on. We had a good laugh and several of the people waiting in the lobby also got a chuckle, as we gave the guys crap for buying us the same sweater. They both swore that they didn't know that the other one was getting it.
During dinner, it was noted that the sweater was to be worn only when we weren't going to be around each other.