Those two mother and daughter pair of the Sun family was used to creating havoc every day. If they weren't creating a fuss over what they got and what they didn't, they would be busy sending Sun Jie over to Yu Dong's house. Because the mer did not know what was right and wrong and treated Yu Dong as a playmate, Yu Dong couldn't treat him harshly.
After all Sun Jie was not at fault, his mother was the one who had pushed the idea of Yu Dong being his friend in Sun Jie's head. Even if Yu Dong was to tell Sun Jie that she was not his friend and the two of them couldn't play with each other, the latter did not understand.
Sometimes Master Sun would come to take his son away but he would be beaten up by Mother Sun. Yu Dong naturally knew that the mother and daughter of the Sun family wanted her to take responsibility for Sun Jie but how could Yu Dong do that? She wasn't an Emperor who wouldn't be satisfied with countless beauties in her harem.