Edvard, you're just so damn charming. ;) You can look into my window any day (I'll even put the taser down)
I decided since I don't really like the guy (he was a little sexist and creepy), I hope he does peer through my window so I can zap him and see how well this taser works. I've never tried it before.
I'm thinking of seducing him to do it like a role play/fantasy thing and then surprising him with a little shot of juice from behind a tree. Does this seem really mean, or defensible?
Threat.
1- He barely knows you, and he's joking about creeping outside your window. I would confront him directly. "Really, so you're a creeper who admits he wants to stalk me while I'm asleep? Thanks for the warning. Now here's a warning for you: I'm a very light sleeper, and have my ways of knowing who's in my yard. (Get a camera.) If I ever catch you invading my personal space, I'll blow your brains out. Is that perfectly clear?"
EDIT: Change your sleeping schedule for a few days, and be sure to check your window at night, during the time he is most likely to come around. Especially now that you made the right choice and dumped the creeper. Make sure you are armed. Grill your roommate relentlessly until he coughs up your charger. A "friend" doesn't fuck with a woman's weapon. Don't give him that power over you.
Be assertive. Most sexual predators are cowards. If he's a good guy, he'll respect your ability to defend yourself. If he isn't, he'll fear it.
2- You ex stalked you at that window, and now part of your tazer is "missing"? That is suspicious. It does not strike me as a coincidence, or something to take lightly. Act accordingly. Stay armed, tell someone you trust you think you are being watched, install a hidden cam on your windowsill, and remain suspicious of your ex and this new guy. Do not let down your guard yet.
Whenever your instincts are telling you something is off, the worst thing you can do is to dismiss them. They are your in-bred survival mechanism. Respect them enough to pay them heed.
It was probably a harmless comment, but you're better off safe than sorry.