月老爷爷把红线换成钢丝吧
[yuè lăo yé yé bă hóng xiàn huàn chéng gāng sī ba]
This nickname references Chinese folklore, where an old man under the moon ties a red string around the wrists of two destined lovers. The humorous twist suggests changing the red string into a steel wire, implying the durability or permanence of a relationship.