It is perfectly understandable and all right to have an imaginary friend. That said, do you really know your imaginary friend enough to be a trusted entity?
Ask yourself: how long have you known your imaginary friend? Most of them appear sometime in childhood and don't go away until you get the standard array of brain drugs prescribed for wackos. Is your childhood imaginary friend still the little kid from early days? Then you may be a Pedo Bear and need to be locked in a box for your own good. If your imaginary pal is, say, Jack the Ripper, you are absolutely okay since you can't be any worse than that character. That's even if you are the one selling body parts on eBay. If your imaginary friend is an exact double of you, he or she probably got fed up with boring and predictable you a long time ago and is looking for the slightest excuse to get out of the relationship.
On the reverse side: how good a friend are you to your imaginary friend? Do you know his or her actual phone number or is it just on speed dial? Birthday? Favorite imaginary food? Think hard about this. Also, consider the thought that you may be the imaginary friend of your imaginary friend.