My thoughts about the main three characters:

Fei: He was new to the work; Max helped him. In the process, they fell in love. I don't blame Fei for running, he didn't ask Max to beat him up. I would flee too if the police were looking for me. Then he fell for Long. Long is the innocence he lost. He is everything he could never be, so at first he tried to resist him. Even hate him, I guess. But Long broke through his wall. When Max came back, it wasn't love but guilt he was feeling. He is doing everything out of guilt, which is holding him back. He will never be truly happy in life, and he knows it. The only thing he can do is remember the time with Long.

Max: The perfect moneyboy who fell for Fei and let his emotion control him. If he had planned it, he could get away without messing up everything. I'm sure he regrets losing Fei for this. Him getting married and having 3 babies shows how he is doing. I am not saying anything about his sexual preference, he can be bi, pan, or just gay. But he does not love his wife. He still loves Fei, but it won't be fair to him if Fei stays with him out of guilt, and he knows this.

Long: Long is like a free bird. I feel like he is the type of character who is pure innocence. He will never be corrupt. He will show you his raw emotions. But you cannot keep him in a cage. He will fly. I felt like Long liked Fei even before he left the village. He went to find him in two cities. But he is not willing to be someone's second choice. That's why he left.

Max's wife is ...creepy.

Having an open ending is sometimes to bad. You can only imagine the choices they would make. Will Long return? Will Fei go to find Long? Or will Max and Fei get together? We can only guess.