You are talking b*llocks again Ian, plain and simple.
"Shake a tail feather" is quite obvious what it's about and you can see the dance on youtube, as are songs about the "back door man", "Lickin stick", "Honey dripping", "your Lovemaker", "Sixty minute men", "Make it last forever" etc etc.
You mention "While you're out looking for sugar" the lyrics are pretty obvious there too never for one moment thought that it was about anything else, and "Band of Gold" was about a newly weds disappointment in her man's performace.
Some of us do actually listen to the lyrics and 'get' black slang. But with Mel & Tim you are just guessing wildly based on a 1989 reference in a rap song, and I am not buying a word of it.
And I am certainly not "crazy" when it comes to soul music.