Being a guy who is in a
very serious relationship (love you baby
), I want to add my two invaluable cents to this.
I do believe that a man should have the guts to defend his fiancee in front of his mother, should she be acting up and critisizing stupid things out of spite. Heck, everyone tends to find fault in the most insignificant features or traits in the other person if there is something else bugging you. Let me ask you this, is your fiancee a single child? If so, it's pretty clear why your MIL suddenly went off on you... you're taking her baby boy away.
I mean, it's a tough call really, because guys don't know how to work with both women in their lives, and they don't want to hurt either. Mediating would be probably the best solution, instead of messing things up with either party. In an earlier relationship my mom was heavily critisizing my gf, and she ended up being right about everything. God bless her heart! Fortunately, there is no issues whatsoever currently, and since my mom loves Megs I somewhat doubt there will ever be any.
By the way, why do I only hear troubles with the MIL... what about the Daddies In Law? Sheesh, women...