Is it just me, or do super friendly and happy people freak you out?

My cousin is seeing some new guy and he’s super friendly and super happy all the time. There’s something about him that makes me uncomfortable and annoyed. I mean, the first time I met him and he’s already offering to give me an oreo cheese cake from his job and stuff. There’s just something about him that I really don’t like and I have no idea why. Now my cousin wants us to go on a double date to vacation somewhere and I don’t want to.

I don’t even know if it’s him being nice that’s the issue. I know a lot of really nice people but they don’t annoy me at all. But this guy, I dont’ know…I have no reason to be uncomfortable or not like him but there’s just something about him that is odd to me.