Paranoia: the paranormal, a pervert, or a possum?

Last night I went to bed early with every intention of, for once, feeling rested and refreshed in the morning. But it was not to be.

I was woken in the middle of the night by the sound of steady breathing. This worked its way into my dreams, waking me slowly, provoking little alarm. Until I realised that it was real, and not part of my imagination. Whereupon I can assure you that waking to hear breathing that is not coming from you, in a room that you know was otherwise empty when you went to sleep, is a TERRIFYING experience.

The breathing was slow and heavy and felt horribly close by. While trying to remain incredibly still I attempted to collect my thoughts. It sounded human. It was coming from the direction of the window that I always leave open at night. I was petrified. It occurred to me that every night I am pretty shameless about getting changed in front of the windows (there are no curtains) - extremely obviously backlit against the inky darkness outside. This normally doesn't worry me. I assume that no-one can see, and if they can, they probably don't care. But now, merely hours later, there was someone in my room, breathing heavily. Bugger.

Just as I was working myself up into a total state, the breathing stopped. Oh my god. The thing had realised I was awake. Quick as a flash I whipped on the light. Nothing. The room was empty. But my gaze was drawn to the wide open window.

I waited a few minutes, decided I was being mad and hearing things that clearly weren't there, turned the light off, and tried to go back to sleep. But, obviously, sleep by this point was impossible, as I was too busy listening intently. I was slightly torn. Part of me wanted to not hear the noise again, but that would mean I had imagined the entire thing and was quite clearly two sandwiches short of a picnic. The breathing started again. Aaaaaaaa! Slowly, very slowly, I made my way over to the window and eased it shut. I could hear the breathing outside. But, blessed relief, it could no longer get in. So, back to bed. Whereupon, after a few minutes break, which lulled me into a false set of security, the breathing moved to the other window. The window right behind my head. 

By this point, I was starting to consider that maybe my hosts hadn't bother to warn me, but my room was actually haunted. By the ghost of a heavy breather. Looking back, it is perhaps a little strange that my mind went there before a more normal conclusion. The breathing got louder (I could still see nothing out the window) when suddenly there was a change. Still steady and deep, but now there was an audible hissing in between. Snake? Surely not. But having had that thought I realised, steady on! This is Australia, everything dangerous/strange/incredibly freaky is animal related. So I typed 'heavy breathing Australian animals' into google (no I'm not kidding, I actually did). The answer was conclusive. It appears that there is no difference between the noise of a rampant peeping tom and a bloody possum. 

The bastard had struck again. In the words of that immortal genius, Withnail: "the fucker will rue the day!"

That being said, I am no closer to knowing how to get rid of him. Although, after last night's intense study of his breathing, it is possible that he is asthmatic.