Traditionally, baby splashdowns are given only for the family's first child, and only men are invited to party.
It’s a male version of the much tamer
baby shower (these are held during the day and guests flick
cotton wool balls into a
cooking pot, give gifts and there’s normally a botchy row).
The pending Father convenes in a pub with his male friends and conduct a last big ‘Leo Sayer’ before the birth of a child.
Ideally the Father will not return home that evening.