Residents of Second Life can "partner" with other residents. A partnership can signify marriage, dating, or even friendship. To create a partnership, one person must send a proposal to another, and if the other party accepts both people are charged 10L$. After accepting a proposal each person's partner will appear in the "Partner" field in their respective profiles. The partnership can be canceled at any time through the "Partners" page and will cost the resident asking for the "divorce" 25L$ (the other person will not be charged).
Partners were introduced in 2004 with the intention of being used to create two person "groups". The original features that were to be implemented were the abilities to co-own land as well as one person being able to change their last name to the others. These ideas were scrapped however.