When I was taught this song, in the early 1960s by a friend of my parents that I always assumed to be a deeply respectable lady, she taught it to me like this:

"Take a (sniff) take a (sniff) take a (sniff) on me
"Everybody take a (sniff) on me
"Hey, hey, everybody take a (sniff) on me"

and so on (actually, I'm not sure if she sang "take" or "have". But the "(sniff)" - and this is the reason I put it in brackets - was not the word "sniff", but you actually sniffed.

I understood it to be a generous offer - "take a sniff of what I have bought and am offering you". When I asked her what (sniff) meant, she told me that it was a funny way of saying "kiss", as far as I remember; do I imagine that I saw a flash of warning into the back of the car from my mother?

It wasn't till many years later that I realised this was a cocaine song - but that was a cokey generation, with songs like Minnie the Moocher suggesting "kicking the gong around" - ie taking cocaine.

As for the word that amuses Senoufou's husband, it's not said now because it was used for so long to demean a group; he finds it funny because it's not in his childhood, being lashed by that sneering word. It has no power over him.