I didn't know!!!!!😢

I've been casually sleeping with this guy for probably 5 months now. He asked me to be his girl 3 moths ago. He's a good guy no complaints about him.

The other night his phone rang he was in the kitchen and told me to just answer it so I did.

Before I could say hello some woman was screaming and said "you need to get your ass back home Daniel won't settle"

I responded with I think you have the wrong number and she's like who the hell are you and where is _____ (my boyfriend)

Long story short he's married with a 4 year old son and I didn't even know.

I'm done with him of course but I feel shitty. I had no idea. I would have never gotten involved if I knew! Am I bad person?