I've tried searching for this, but short of day of responsibilities, I can't find any list that discusses when someone is or isn't hosting a wedding. My fiance's parents have made a sizable contribution to the wedding and his mom has been far more helpful in planning than my own mom has been. But when I suggested we include their names on the invitation, my parents flipped out. I think it is really rude not to include his parents given what they've done and I don't see why they wouldn't be considered hosts. Thoughts?