Thank you bigbadbubba1337, funny stuff.
jjron99, If I was in your shoes I would go to SG. The only way I could justify going to the wedding instead of SG would be if I had not already paid for the weekend.
Otherwise, it's not your problem. You told them you were going already. The wedding will go on whether you are there or not. If she is "the one" and you couldn't think of disappointing her, you would not even be posting your dilemma here. Also, a third wedding is a joke in my opinion. The mother is just dating somebody else and getting a legal document to prove she believes it is serious at this moment.