小三扶正了也终究是小三
[xiăo sān fú zhèng le yĕ zhōng jiū shì xiăo sān]
This nickname reflects a self-deprecating attitude. 'Xiao San' refers to a mistress or someone who interferes in another's marriage, despite sometimes being 'officially recognized', the status still remains as secondary. The user may imply that they cannot be acknowledged officially or truly, possibly referring to their inferior social position, relationships, or some aspect where they can't get formal recognition.