A popular temporary marriage, available in Christian Tudor England and Scotland. Revived recently as a form of marriage ceremony among neopagans. Some consider treating it as temporary for a year and a day at which point, the couple will decide whether to be married fully or to separate without commitment. However, many neopagans ask why their marriage should not be just as binding as Christian marriage, as they perceive it as simply a pagan version of marriage.
There are many ceremonies. There is not a traditional one, but Janet Farrar and Stewart Farrar in A Witches Bible provided one which is considered authoritative among Gardnerian and Alexandrian Witches.
I feel no need to reproduce it here because I do not use magic as a religion, but as a science to explore the unknown. I feel no need to involve religion in marriage.
I will however caution against spiritually binding two people together. While at this time, in this life they might get on well. This might not be the case in the future or later incarnations. It’s entirely possible their gender will change when they come back and not match with their sexuality. They may even come back as related such as mother and daughter and not be able to pursue the relationship they have been bound to. While the ceremony should be beautiful and recognise their love, in my opinion it is more suitable to bless their union rather than bind them together. Just some thoughts. Like I said, religion need not be a part of marriage and magic need not emulate Christianity’s social rituals unless you feel that is important to you.