If you build your family tree online, please read the following article: How do I add more than one partner in my online tree?
To add another spouse/partner to the tree, click ‘EDIT’ on the person’s card.
Select ‘Spouses’ and ‘Add Spouse’.
Click ‘YES’ on the message asking if you’re sure you want to add an extra spouse.
Add the spouse’s details. Don’t forget to set the relationship status at the bottom of this window. The default is Married! Click ‘OK’.
Click on a spouse/partner’s name here to switch between them.