Meaning:
“灯具店” means “lamp store,” and “老板” means “owner.” This term, coined by Chinese netizens, derives from another term “电灯泡” (diàndēngpào, literally meaning “a light bulb” and often used as a metaphor for “a third wheel,” who is the unwanted company to a couple on a date). A “lamp store owner” humorously refers to someone who is super comfortable sticking around a couple as they pack on a lot of PDA (public display of affection).
Example:
A: 周末你去哪里玩了?
Zhōumò nǐ qù nǎlǐ wán le?
Where did you go over the weekend?
B: 我跟丽丽和她男朋友一起去爬山了。
Wǒ gēn lìlì hé tā nánpéngyou yīqǐ qù páshān le。
I went hiking the mountain with Lili and her boyfriend.
A: 这一对无时无刻不在秀恩爱,你可真是个灯具店老板。
Zhè yīduì wúshí-wúkè bú zài xiùēn’ài,nǐ kě zhēnshì ge dēn jùdiàn lǎobǎn。
This couple is packing on a lot of PDA all the time. You are such a strong-willed and comfortable third wheel.