Drinking buddy
A euphemism for a person with whom you have an intimate relationship, but cannot, due to fuckumstances call a best friend, boyfriend, girlfriend.
Example:
A: Those two are always together, is that his wife?
B: Nah, they're married to other people; that's his drinking buddy.
A: Those two are always together, is that his wife?
B: Nah, they're married to other people; that's his drinking buddy.