Kyle and I have been together a few years now and we've come to a mutual understanding about something. Don't ever try/accidentally happen to scare each other.
A couple weeks before we got married, Kyle was living in our apartment and I was living with my sister. We'd been together after work, I left to go home, forgot something in the apartment, and returned a little while later. I knocked on the door, rang the doorbell and Kyle never answered. I let myself in and yelled from the door that I was there so he wouldn't be freaked out or something. I could hear him talking on the phone and doing laundry so I walked through the living room towards the hallway, where I knew he'd be. It was about then that he heard me, came in the living room and flipped out. Throwing punches and all.
He hadn't heard me knock.
He hadn't heard me ring the doorbell.
He hadn't heard me announce my presence.
He was, in fact, in his underwear.
And he thought I was a burglar.
The proceeding scream and flailing of arms still brings tears of laughter to my eyes.
A few weeks after we got married, I had an embarrassing case of the hiccups (my hiccups are really quite dreadful). I got in the shower, minding my own business, when Kyle comes in, opens the door and yells.
His motive was to scare the hiccups out of me.
My rationale was he was an ax murderer coming to chop me up into showery pieces.
I screamed hysterically and threw shower items at him.
In shock, he retreated from the bathroom amidst a shower of apologies.
So there you go. We are now not ever allowed to scare each other. If I'm in a room by myself, Kyle will cautiously announce his presence before entering so as to not scare the living crap out of me.