A movie I watched but forgot the title

it was a Asian film, Chinese I think. two young male and female lovers who grew up over the years together. in the early scene of the movie, they sneaked from school to attend a festival which ended in chaos. they grew a bit and the lady came to boys hostel and had sex with another boy just to piss the boyfriend. Later at the hospital, the boyfriend claimed responsibility for the pregnancy out of the love he has for her
there was also a scene where the group of friends had a fight in a bar after an intense conversation. at the end, they separated and the boyfriend moved to USA