I would have chosen one of two options:
A) Open the window wide and make outrageous sex sounds, with lots of screaming, moaning and bed screeching until the sweet darlings shut up..
B) If they had actually woken me up at 8 am on a Sunday, I would probably just screamed "SHUT THE F* UP!!!" from the bedroom at the top of my lungs (after all, I would be inside of my house and at that time in the morning, I would have the right to make as much noise as I wanted and use as much profanity as I wanted).
Are people really asking why he did not go and talk to the parents? Well, it's bloody obvious: it was Sunday morning, he was trying to sleep and likely wearing underwear or nothing. If he had to get up, get dressed and walk to the neighbours, he would have to leave the bed, and hence what the hell would be the point of complaining.
But hey, I am hot-blooded and have always believed kids are tougher and can deal with much more than most people here, which would probably feel the need to take them to the child psychiatrist after the traumatising event. As if kids couldn't deal with being told to shut up.