To start - a little background information on my fiance and myself. His parents divorced (in quite the messy fashion) when he was about 7 years old. His dad has since remarried, divorced again, and now newly engaged to someone whom everyone else in the family (myself included) cannot stand. His mom never remarried. His mom hates her ex-husband's current choice in mate so much that we've all been afraid to tell her he got engaged. We actually still have no clarification on whether or not she knows. My parents have been married for almost 38 years, so this whole blended and re-blended family situation is completely foreign to me.
My main question - how much should I include the father of the groom's SO? They haven't been really part of the planning process at all. We don't necessarily have the best relationship with her. Recently she said something about wanting us to give her grandkids already, and my fiance responded (in much more colorful language than I would use) that our children would NEVER call her "grandma." She also been known to bash our religion (we're practicing Catholics and my mom was a nun - like in the Sound Of Music) to my face. That being said, the father of the groom wants his fiance included in everything to the same level as the MOB ant the MOG. We asked that she not attend our menu tasting (we would have had to pay extra for her as our 6 seats for the tasting were included as part of our package). He threw a fit, and my fiance and he argued for a week. Over a dinner. The FOG recently asked if his fiance was in the wedding, to which I said to my fiance: "ABSOLUTELY NOT!" We have already assigned the readings and the other tasks during the ceremony, and it would be rude to have her escorted in with the mothers since she is neither of our mothers or a step mother to us. Not to mention, it's a Catholic ceremony, and since she has formally renounced the Faith (part of her reasoning in bashing it to my face), we cannot have her be part of the ceremony without getting in serious trouble ourselves.
Where do I draw the line? My mom thought it would be nice to give her a corsage and to have her announced at the reception with the FOG - which could be tricky considering we don't know if the MOG knows about the engagement. The fact that the FOG is acting like a child over this makes me want to not give her anything at all. She is not that close with us, and I see no reason for awarding this woman a prize for being a home-wrecker (she's the reason that FOG and wife #2 got divorced). On the other hand, I want to keep the peace for the sake of my fiance, who so desperately seeks his dad's approval that he'll sacrifice his own happiness to do whatever his dad wants. Any suggestions on how to handle this crazy situation?