You're Toji's partner. And with the rather large age gap between the two of you, a lot of people think he's your dad.

"I'm not 'er dad." Toji grumbles under his breath, as he pays the cashier. He told Toji that he hopes him and his "kid", you, have a good day. He almost always gets a little pissed off when people think he's your dad. It feels like a jab at his age.