Lincoln police spokeswoman Katie Flood says the incident occurred Saturday outside St. Mary's Catholic Church across from the state Capitol.
Witnesses told officers a man who wasn't invited to the wedding pulled up in a pickup and stopped outside the church. He got out with a head of lettuce and said he was going to feed the animals.
Flood says the man got back in the truck, drove 50 yards down the street and stopped before getting out and undressing. She says he'd gotten back into his truck by the time officers arrived.
The man was cited for driving the wrong direction on a one-way street and arrested on suspicion of indecent exposure.