She has such high demands and what would she give in return? Her companionship and support? Bah, she would care only about her little bastard. Loyalty? Nah, she'd jump off your train the first chance she'd get. The only thing she has - her used up and torn to pieces roastbeef? And even that is not guaranteed! You are not entitled to sex! Only Chad can be!
All and all, that is hardly a fair exchange. Single mothers should be hanged, drawn and quartered for the greater good.