Getting a Little Too Friendly?

I posted a while ago about how I felt my how my co-teacher, Yogesh, and I were really starting to get along both on a friendship and professional level. We had this conversation earlier today. I'm not exactly sure what it indicates.

Yogesh:(seeing some of our students walking across the courtyard) Look, those are some of our kids.. OUR STUDENTS! I meant our students!
Me: Yes, our students. We are not married.
Yogesh: (laughs and sticks out his hand for a high-five)

Maybe this is why people keep saying that it's better to keep your personal life out of the workplace...