This will be the third wedding I wasn't invited to. He has attended two of them without me already.
Most Helpful Guy
Here's my take on this wedding invitation. When a person is invited to a wedding it is assumed that they will also bring a significant other, even if he/she are a groomsman/bridesmaid. I have never seen a wedding invitation to an individual that does not by proxy assume a guest will accompany them. In the RSVP there is a box (usually) to indicate whether you will be attending alone or with a guest.
(Perhaps you can double check this).
I hope you both go to this wedding, it has nothing to do if you know the bridal party or not.
Good Luck and have fun.2