The word "if" seems to Ye Er to be beautiful and luxurious: if he had not met Cheng Yi, if he had just met Cheng Yi, if Cheng Yi was not Cheng Yi, then Ye Er would not have tears on his face when he thinks of that time. . . Salty and a bit astringent.
Salty and a bit astringent---this is how Ye Er feels when he thinks of Cheng Yi.