我是你谁萌比媳妇
[wŏ shì nĭ shéi méng bĭ xí fù]
With playful language, this can be translated to 'Am I not cuter (in terms of 'moe'—a Japanese expression of adorableness popular in China too)—comparing myself to your wife?' indicating a lighthearted, somewhat flirtatious way of addressing someone, comparing one's own charm (or cuteness) against another important relationship figure—in a friendly teasing manner, likely used amongst very close friends or as self-deprecating humor towards crushes or romantic interests.