It's not that the two beauties Shuiyue and Jinghua don't believe in Luo Yang's strong physique, but the speed of pregnancy isn't much related to physical strength.
Even if Luo Yang were as strong as an ox, he might not be able to get Shuiyue and Jinghua pregnant with his child in just one go.
You could say, for a girl to get pregnant, a guy can only do his best.
Whether it's one try that'll lead to a beloved's belly getting big or it takes multiple tries, that's still an unknown.
To put it more clearly, pregnancy isn't decided by human will alone.
Though subjective reasons are quite important, they're not absolute.
Hearing Luo Yang speak so confidently, Shuiyue and Jinghua giggled.
After they finished laughing, Shuiyue shyly said, "Husband, you think it's like brewing tea, ready to drink as soon as it's steeped. Getting pregnant isn't that simple. It requires the right timing and conditions."