This plugin is currently on ALPHA, so expect some features coming soon, anyways onto the point you can marry players on the server, this is like a roleplay theme, but you can add it to your server if you wish.
/marry <username> - marry's any player even yourself!
Private Chat for you and your partner
(pm me for more suggestions)
If you do /marry itself it will bring an error so don't do that.
KEEP IN MIND THIS IS ALPHA STAGE!