Hi, Waawe. 22 for 1! I wonder if that is because this is a difficult one? or because no one who understands the lyrics is game to print an answer?
Neil Young sings on 'Rust Never Sleeps': 'Welfare mothers make better lovers.' Nick Cave is, I think, alluding to the way that women's bodies changes after childbirth. It's an age-old paradox, Waawe: men marry women for their physical beauty. The women have a couple of kids -- which 'blasts' (various parts of) their bodies -- and then the marriage is about working hard to pay dentist's bill, not spontaneous sex with the woman that you fell in love/lust with. Look up the word 'episiotomy.'
Mark in Perth