Living in an apartment, I understand and have no problem with this happening from time to time (even when they decide to go at it again just as I'm getting dressed for work early this morning!), but the one thing that really annoys me about this incident is that I was just about to fall asleep as it started! If they had waited another ten minutes I would have slept through the whole thing, instead by the time it's all over, I'm wide-awake and just can't get myself to fall back to sleep for another two hours!!
I need to go to bed earlier. :p