Re: Yes, I am ashamed of my country
"e.g. the drunken one night stand that you dont hear from for 10 months who shows up with kid in tow demanding money. She told you she was on the pill / said she was infertile / whatever....."
I can't speak for the UK, but here in the states even having a formal contract to that effect won't excuse you from paying child support to her. Nor are those payments predicated on need - she might be wealthy and you might be poor, but you'd still owe her support.