My Mother`s Husband

Okay, here`s a touchy one. We`re trying to get the wording on the invitations down, and as the groom, I`d like my parents` names following mine, as is more or less custom in the South. But, my parents are divorced, have been for years. No big deal, mom first then Mr. And Mrs. Dad. (Separated by an "and"? I don`t know, you tell me.)

But wait, there`s more! Mom has been divorced from #2 (my former step-father) for seven years. At the end of December she went on a first date with this guy nobody knew, and two weeks to the day later, he became #3. So now instead of:

Rob
Son of
Ms. Mom (name she`s had for 20+ years)
Mr. And Mrs. Dad

Instead I have:

Rob
Son of
Mrs. Guy I`ve Known For Four Months And Am Not At All Sure I Like Yet
Mr. And Mrs. Dad

You can see my dilemma. I have maybe spent five or six hours total in the presence of this guy, and I just simply DO NOT LIKE the fact that his name IS on my invitation. I feel like my mom`s name is NOT represented. I would even be okay if it had her first name and his last name, but I just do not like my wedding invitation having the full name of a guy I had never heard of four and a half months ago.

Is this just something I have to suck up? These situations aren`t covered in etiquette guides.

Thanks....

-Rob