內牛滿面 [nèi niú mǎn miàn] Tears stream down the face. A phonetic deviation of the Chinese idiom 淚流滿面 [lèi liú mǎn miàn]. This slang term is often used to describe excitement rather than sadness.
When I was little I never understood the concepts of the actual age and the nominal age. Just now a friend said, “The actual age is the time span since you came out of your mother’s body, while the nominal age is the time span since you came out of your father’s body.” With tears all over my face, I immediately understood [the difference].
[Note: Some Chinese people use the nominal age (the current year-the birth year+1) instead of the actual age (the current year-the birth year).]