Neighbor below my office tried to 'PAIR UP' w/ my mac via BLUETOOTH

This is the deal, I live in an apartment and I have my home office in the spare room, which incidentally is directly above a teenager who's bedroom is right below my office. There are, of course many people in the building with computers etc, and there are about four wireless networks (that I can see) at any given time. What I did not consider was that my computer could be vulnerable (wirelessly) via bluetooth, mainly because I don't use it that much and certainly not on a regular basis.

I have a bluetooth mouse that I use only occasionally, preferring the hard wired version. Also, when I travel, I do have a portable BT printer (a Canon) which I practically never use at home. But, probably because of my lack of using the bluetooth technology on a regular basis, never really thought of it... except for yesterday..

I was at my desk working, and a screen popped up saying something to the effect of a certain bluetooth device, the name for the 'device' was actually the teenager's first name!.. so it was easy to know who it belonged to, requesting to 'pair up' or something like that w/ my mac. Of course I denied it, but then, and for the first time, realized that I hadn't paid ANY attention to bluetooth as an access to my computer. Which made me wonder what ELSE I didn't know about BT. So that's why I'm here posting my question & concerns.

I realize now, that I had left bluetooth 'ON' as well as it was 'discoverable'. After this event, I obviously turned the discoverable OFF and also just turned BT off altogether - until I figure out what I need to know to keep my computer safe. Which precisely is my question. What do I need to do w/ bluetooth to keep my computer secure and keep my nosey and tech-savvy neighbor out of my computer - and still be able to use other BT devices myself, if I want to??

I don't know what kind of BT device he had, nor do I know if he's tried this before. I was ignorant about the possibility, honestly. So, since I don't know, what do I need to do to keep this kid out of my computer via BT and still have the possibility of using bluetooth devices myself? I'm somewhat clueless of what's possible simply because I've used it only in limited and occasional situations.

Any particulars on this issue will be appreciated.

Best regards.