Quote From: seecheyleBefore a couple gets married, sometimes before they are even engaged, the in-law jokes start. More times than not on television, in books, movies, etc..., the in-law relationships are often depicted as dysfunctional, and most often the relationship that is dysfunctional is the mother-in-law/daughter-in-law relationship.  
As a mother of 2 young children, I'd like to think that when they marry, I will not be the stereotypical mother-in-law. But, being realistic, mother/son relationships are close. For years and years we will have been the ones to feed him, hug him, hold him, and love him in a way that only a mother could. When someone else starts to "take care" of him, making his meals, washing his clothes, wiping off his milk mustaches :-), it is a completely human feeling to miss having that place in his life. I am getting choked up thinking about it and my son is only two!  
 
That being said, that does not mean that the relationship between the mother-in-law and daughter-in-law has to be a strained contest to "take care" of son/husband the best. I think that maybe the stereotypes about this relationship may put us on guard before we even bother to establish a relationship beyond (daughter-in-law) "my boyfriend's mother", or (mother-in-law) "the girl he's seeing." I believe that stereotypes can often damage a relationship before it even starts. 
 
It's so easy for me to see that it would be best to realize that both myself and his future wife ::gulp:: love my son very much. That is probably the most important thing we'll have in common to build a relationship on and then hopefully build a friendship even beyond that. BUT, that is so much easier said than done and I can only hope I remember this when it's time. :-) 
I think what you said about "taking care" of the son/husband is the crux of the problem. The mother is done mothering and must establish a new kind of relationship with her son and she sees the wife as the new mother. Whereas wives do not want to "mother" their husbands. Wives want a grown man that is able to operate a stove, operate a washing machine, and knows how to drink milk without getting a mustache. A mother takes care of child care needs, a wife takes care of adult relationship needs. It's very different and problems between the two women arise when either one or both forget there are differences.