Wendy, I don't believe that there is any reasonable way to get the videotape back willingly.
The problem that I see is the 'ownership' of the tape. I assume that you are both on it, so you could both claim 'content ownership' as the 'artists'. And whoever made the video could claim 'creative ownership'. And whoever possesses the tape could claim 'possession ownership'.
Some or all of these issues would need to be determined by a court at law in order for you to get an 'order' returning the tape to you. And as public record, the fact that the tape existed would be available to anyone who reads the casefile (I don't know if 'existence' is a concern of yours or not).
Unless you can get him to turn the tape over to you willingly or unless you have a valid ownership claim, you will probably have to go through the necessity of a legal proceeding to determine ownership.
