我是你妈的情人
[wŏ shì nĭ mā de qíng rén]
Translation-wise it means 'I am your mom's lover', however, using familial terms humorously in titles like online handles or post tags is very popular among internet-savvy generations as a colloquial form of showing closeness or familiarity. Yet it should be noticed this might come across rudely in different cultural settings.