Search Results: call me baby

Soo long story short
My best friend of 2 years now
We help each other out
He calls me baby and he called me babygirl today
We both make love to each other
He very caring and respectful
He stood up for our friendship towards his ex.
We can't get each other out of our mind

A guy I've gotten to know and I often engage in a lot of banter.
We have the same sense of humor, so we often call one another ugly names and then laugh our asses off.
He calls me Quasimodo, I call him Dickhead. It's something we thoroughly enjoy.
We don't hang out outside of our mutual community, but we do often spend time together when we're there.
Recently I joked about his behaviour to which he replied "but you still love me" then waited for my reply. I pinched my fingers together a eventually said "just a tiny bit, but only if it's mutual," he replied by pinching his fingers like I did and said "just a tiny bit". Give two playful punches in my belly and walked away.
I jokingly exclaimed "Hey, my baby!" To which he replied "Doesn't it sit on your backside?" Referring to my ass. I laughed along and said it was a conjoined twin, and the two of us kept joking about my "twins" for a minute before I left.
We have interactions like this more often than not, which is why I thought he might be interested. However, I just now learned he is in a relationship with someone.
Is this kind of behaviour normal when you're in a relationship or would you consider it (emotional) cheating or whatever term you'd use?