FI's best man told us last week that he and his girlfriend may be bringing his mom to the wedding and asked if that was okay. The best man didn't say why his mom might be coming with him and asking him felt kind of nosy. We decided to just go with it and asked for his mom's name for the invitation.
Since our invitations go out at the end of this month, I was thinking about it last night and realized I have no idea how to address an invitation for the above situation. Sending the best man's mom her own invitation doesn't really feel right, since neither FI nor I have met her before. Under normal circumstances, she wouldn't have been invited. Can I include her on the invitation for the best man and his girlfriend? How would that be addressed? Our invitations don't have inner envelopes.
Thank you in advance for your help!