That very first-emerging part of the ejaculate squirt contains sperm that are more numerous, mobile .
Armed police moved in on a naked woman after she stripped and lay in front of an ambulance to stop it taking her husband's suspected lover to hospital.
Zhang Shih, 38 - from Linyi, Shandong province, eastern China - allegedly ran down neighbour Wang Lu and her four-year-old daughter in fury over over the suspected fling.
But when emergency services arrived she did everything she could to ensure neither was able to get swift, life-saving treatment - even as officers pointed guns at her naked body.
'She kept everyone who tried to help them away,' said a police spokesman.
'Then when an ambulance turned up she stripped off all her clothes and lay down in front of the vehicle to stop it taking the victims to hospital.'
Enraged Zhang is accused of running down Mrs Wang and her daughter with her car after an argument where she confronted her husband about his infidelities.
The mother-of-two then stood guard over the two seriously injured victims to stop anyone offering them first aid, claimed police.
She even allegedly punched a paramedic treating her rival's young daughter, making the ambulanceman drop the girl - who later died of her injuries.
Now Zhang - a primary school teacher - is facing murder and attempted murder charges, say prosecutors.
If found guilty she faces the death penalty.
'This was no crime of passion. She stopped the two victims from receiving medical treatment for nearly half an hour,' said a prosecutor.