Should I Tell People I’m Joking Or Not?

A friend recently posted how he had some of those Nest cameras on his house and was alerted while on vacation to the fact that some strange person inexplicably dropped off a box of lizards on his porch. The Nest cameras didn’t actually give that level of detail, but you get the idea and this is what the alert eventually led him to discover. I decided to make a joke on his post about it. He has a thing for crusading against scam artists, often in creative and humorous ways, so I commented:

Presents of lizards are standard for apologies in Nigeria. One of the scammers you took down must be trying to assuage your anger.

Then I wondered, should I mention that I’m joking? I’m sure he’d get it, but…would everyone else he knows who sees it? Would someone really think this is a custom in Nigeria? Lizard presents? It seems ridiculous, but people sometimes end up believing quite ridiculous things…often on Facebook. I wanted to say something mildly witty, not contribute to American misconceptions about Nigeria.

Could someone think I’m serious? Should I have been more obvious I was making crap up?