Role of the Mother-in-Law

I will post this quick since I have got to get out of the house but I am wondering if anyone else has this experience....

I have begun seeing a pattern and it is making me crazy! My fiance grew up in a very "accepting" household and by accepting I mean blind support for anything he wanted to do....I am talking when he was an adolescent here. He even dropped out of high school and his mother though he shouldn't but it was okay so long as it made him happy.

Don't get me wrong, his mother (a mother of 4) obviously loves her children very much and means well. However this woman is soooo increadibly blind to the world around her. I am 100% convinced she is the "source" (genetically) of my fiance's ADHD. Also keep in mind that everyone (not me) is very happy keeping her in the dark and letting her believe what she wants to believe. My fiance has chosen to not tell his parents about his ADHD.

She has  openly said that she does not know why any of her children have to leave the house. It actually confuses her. When it comes to my ADHDer, she has taken the stance (and I overheard I was not purpously overhearing) that she "knows he has made a new FRIEND in me and it good to have friends come in and out of his life but eventually he needs to come home and be with his family". And she likes me! Trust me I know this! I want to scream.

That is only a little background though to my point. It seems as if every time he sees her, weeks and weeks of ADHD progress and getting him organized, and AWAY from the excuses he grew up with, after he sees her he comes home and sometimes it's so bad that it is as if months of work has reversed. She is a well meaning woman and I think that when he sees her, she makes him feel so perfect that he forgets about his ADHD progress. He was diagnosed after my suspicions at the age of 27...and once again, his mom nor dad have any clue about his ADHD because although his mom has it, this people live in a world that is not reality.

I know this may all sound confusing and I will answer any questions. I am just wondering if anyone else has a mother-in-law that brings out all the "worst" aspects of ADHD in their significant other?