How do y’all feel about work wife/hubby?

It is 3 a.m. and my brain decided to remember a random moment in time at my job where this married man was calling my coworker his work wife. Tbh I thought it was weird but they were older and I didn't know if this was a platonic situation or it was just "how the older people are" because other older people started using those terms too at my job. I feel like since if I found out my bf was calling some coworker his work wife I would leave. So what is the point of this? What does this acheieve? What compells others to fake marry a coworker? I feel like that is weird. Work partner aficionados, please tell me.