8 year old starting to fake lisp

[Imhereforthecake]

Over the last week my 8 year old has starting 'fake lisping'.
I keep correcting him, I have no idea where it has come from!
His speech was perfect beforehand. No wobbly teeth or anything like that.
I'm worried it will stick!
Anyone had the same experience? How can I stop it?

Honestly, I'd just ignore it completely. If he wants something, just tell him you'll listen when he talks properly.

I did this as a child because my friend had one and I was jealous! I got bored after a while and stopped! Totally ignore it.