Lyric discussion by Eurybiades 

Cover art for We Real Cool lyrics by Nick Cave and the Bad Seeds

I think it’s more likely to be about his son Jethro or maybe Luke (more likely Jethro as I don’t think he would have measured Luke, also Jethro thinks he’s pretty fucken cool).

Jethro if you're reading this call your dad.

ok the 'Spilling down all over you girl' line does not work with my view above. So I'll change it to about an old flame, which is harder to nail down as good old nick has had a few, but maybe Viviane or Beau or someone not known to Wikipedia or therefore me.