Gene Simmons Family Jewels "Happy Birthday to Whom??"?

Question

So this "Mary" person, who was she??? It seems like Shannon and Tracy had no clue who she was, and I missed the end.

How did they end up at that party?

Answer 1

that show is boring as h**l.  i didnt even know people watched it.

Answer 2

Mary is a fan.. Her friend wrote her to see if she would come for a surprise for the party.. but sharon didn't get that part of the letter.. so they didn't know anyone.