Classic thread. So good to find out I'm not just a psycho.
I start thinking of things they (she in particular, though I am meaner to him) will do to annoy me the minute I know they are coming over/we are going there.
When we first told them I was pg we weren't married, and their faces ACTUALLY fell (whilst saying totally unconvincingly 'oh, that's nice news'). When I was 12 weeks she said I was 'letting myself go' then got upset, cried and locked herself in my room because I had been so insensitive as to think she might have been being mean.
When DD was born they came to the hospital uninvited, then when with DD 12 days old we made the 4hr round trip to theirs for his 60th, she said 'well, at least you've slimmed down a bit - last time I saw you you didn't look like you'd even had the baby!' (obvious retort here, given that she's about size 24, was 'well you don't look like you ever had yours and they're 31 and 29' - I restrained myself.)
She is CONSTANTLY saying stuff to DD like 'your mummy won't let you have that'; 'ok I'll change your nappy because your HORRIBLE parents won't', and also confuses her if she's eating something and obviously enjoying it (she's 20 months) by saying something like 'oh, you don't like that much, do you?'
She is really negative about everything, picks fault in everything I say, always tries to contradict me (I am - I would say clearly - much cleverer than she is and yet she thinks she's the bees knees, constantly referring to herself as an 'intellectual snob' as if it's a badge of honour). DH can do NO WRONG, naturally (he is her first born and she had two boys).
They are great and look after DD much more and better than my parents , but always, ALWAYS try and tell me things about MY daughter!! 'Her feet have shrunk' - no they fucking haven't.
I can't even bear to go to their house. I am a horrible, horrible DIL (but I think I hide it quite well).
I think whoever said it's the knowledge that you're stuck with them that makes it so much more difficult to be the lovely, calm, tolerant people we usually are was bang on. I have fretted many a time about how I just can't tolerate things about her that I would at least suffer in others. She is (kind of) well-meaning and I think she does love me in her weird way, but she's just SO FUCKING ANNOYING.
Phew, long post.