I have been with my fiance for almost 2 years, he was always a bit odd but I thought he was just 'quirky' and he did make me laugh and all my family loved him, he would play practical jokes on people and whilst he was sometimes a bit ott I thought some people just dont take much seriously, anyway we moved in together 2 months ago and he seems to have turned totally nuts and I'm regretting giving up my old house. I cant talk to my friends as they just burst out laughing saying he sounds great or half the time they think I'm making it up and all my family still thinks he's great apart from my grandmother who thinks he has a screw loose and that I should get rid.
A couple of nights ago I went into the kitchen to find tea bags splattered up the cupboards, my son is only 7 so wouldnt have been messing around with hot water so I asked DP what he had been doing and he fell about laughing asking what I had seen, there were 2 wet teabags stuck to the cupboard with tea dribbling down them and onto the floor and while it might sound funny to anyone else the idea of a grown man slinging wet teabags at the kitchen cupboards is just bizare to me and it has also stained the cupboards.
I bought some satin underwear from anne summers with my birthday money a couple of weeks ago and I came home from work a day later to find the dog ripping them up 
turns out DP and tried to dress the dog in them ready for me coming home and the dog had got pissed off and destroyed them, again DP was creased up laughing and hasnt even offered to replace them and I'm more annoyed as they were bought with money from my eldery grandparents.
a few days ago I asked him to put some sun cream on my son whilst I got his bag ready and I came downstairs to find purple sun cream all over his face, hair and uniform, as well as the carpet and settee. son said DP just suddenly went nuts and started squirting it all over the place, I then had a huge performance from son who was refusing to go to school covered in sun cream.
Lastly I asked him to give the bedroom a quick tidy yesterday as the plumber was due to fix the boiler, 10 minutes later I went upstairs to find all the clothes from the wardrobe all over the bedroom, the printer paper all ripped up and thrown all over the place and the bed matress on the floor, DP was sat in the corner of the room laughing like a mad man, I ended up having to ignore the door when the plumber arrived as I darnt let him in.
I cant even talk to him because he just bursts out laughing but its not funny anymore, he's ruining all my things and god knows what the neighbours think when they hear him screaming and making noises etc.
Theres loads of other stuff he's done too.
Is this bad enough to leave someone over? Could there be something wrong with him (seriously, as in medically) am I just being a misery? He says Im old before my time but I dont know anyone who acts like he does. We're both 27.