Why he took him to work?.. so what the meaning with have to wearing the earing too?

The earring is from him, so it marks him as his. It's a dominance thing. Also, I think he's trying to get him an honest job?

Maybe he know someone who is bi or gay there? Idk in reality but men's earring symbolize 'taken' for gays, normal couple rings for hetero, if he tian also wear the earring, its clear as day he is lowkey claiming guanshan