Hello, mate!
(Practicing my Australian.* How am I doing?)

I'm so glad the timing worked out for this couch exchange. I'll be crashing on yours by the time you get to mine.** If you run into any problems, just find Alyssa. She'll help you out with whatever you need.***

Your couch-swapping mate,
Rick

*That's cute. Go have fun in Australia and leave ME - your girlfriend for an entire semester - to waste away on campus, alone.

**Um, think again. Your couch is already taken.

***Great. Now I've got to find a place for the (unbelievably hot, it turns out) Aussie to crash. But there's only one couch available: the one in my dorm room. . . .