妈妈总说毛爷爷不爱我
[mā mā zŏng shuō máo yé yé bù ài wŏ]
In a humorous tone, the nickname references a person feeling that their grandma (or grandpa; there is an ambiguous term in the original Chinese text) does not show them enough love. Here, '毛爷爷' could be understood affectionately as grandmother/father but has additional cultural significance referencing the Chinese leader Mao Zedong.