你是我的小苹果一口咬定不放手
[nĭ shì wŏ de xiăo píng guŏ yī kŏu yăo dìng bù fàng shŏu]
This internet name uses a metaphor from the song 'Little Apple'. It implies a person is as appealing as an apple and once found, the speaker is determined not to let go of that person, expressing deep affection.