Swinging at the Castle

Svante and Inga are engaged to be married and there doesn't seem to be very much stopping them: The only things are that Svante has some difficulty in selling his apartment (because the house in which it is in is so noisy) and that he's sleepwalking once every full moon and ends up on the roof, with bruises. However, the rich Sophie meets Svante and wants him herself. After a couple of embarrassing situations, which Svante can't explain, (Sophie even brings him to her castle) Inga thinks that he loves Sophie and leaves him. But, Inga has friends, who are not going to let her lose her loved one that easily...