wait can someone actually explain to me how yiyi is rourou's dad too? like i forgot

He was the one who took care of him for years so he can also be considered as Rourou's father.

Yiyi went to have a kid through a surrogate, but Feng had the sperm swaped so FengFeng is RouRou's biological father technically

ohh ok so yiyi is the one who raised him but feng is the biological dad

I want to, but there already many explain XD