I run my knife over my gf when she sleeps
That's very dangerous. Did she consent about you doing this to her?
No, I just love scaring people I care about.
Running your knife over someone while they are sleeping is creepy. If she wakes up to doing that she will be afraid and call police.
I was bored, you never been bored before?
If you're bored then you can do other things, just not running a knife over your girlfriend as that can end up badly if you accidentally cut her with it. She may press charges and you may end up in jail, so I strongly suggest other pastime activities that are much safer.