Lol I got an ad for a cheap showerhead when I opened FML after reading this. Seeing what happened to you, I'm not gonna get it :P

You should hang your head in shame, because that pun was just cheap. You need to face that fact, even if it is hard.

the pun was cheaper than the shower head

I agree. He probably didn't tighten it properly.

It was clearly tight enough for pressure to build under the shower head though, since OP said it burst out

For all we know he may have left it loose on purpose as a practical joke.

It can't have been loose, or it would have simply fallen off, not "burst." It's more likely that the shower head was designed to be used with a lower water pressure, or that the shower head itself has a manufacturing flaw that caused insufficient space for the water to flow through. Maybe even both.

27, it absolutely could have been loose. Think about it: it's on tightly enough that it won't fall off by itself, but will after some water pressure builds up. Especially if he crossthreaded it or stripped the threads.

If it had been loose enough, it would have fallen off without much fanfare once the pressure built up enough.

*Fails miserably*