It's something I noticed for the first time hearing this song since I became an adult and listening to the lyrics, especially the first verse:

Hey I was just a skinny lad...Left alone with big fat Fanny, She was such a naughty nanny, Heap big woman you made a bad boy out of me

It seems pretty self-explanatory to me, or am I making a big deal out of nothing? I know I'm sometimes overly-sensitive about this kind of thing

But if it is about a young boy (young enough to still need a nanny, apparently) losing his virginity to an adult woman, are people just not bothered by the connotations, considering that it's still a very popular and well-loved song?