Are these red flags?

Laina • GIRL POWER!
So I met someone exactly a month ago.
He was engaged 5 months ago to his girlfriend of 8 years on/off
They have a 19 month old
They have a house together, but after the breakup he has been house hunting 
I told him we could be just friends, because his life was messy, but we ended up falling for each other platonically. About a week ago we slept together, and needless to say it was f***ing amazing. 
Long story short, our relationship is super dope and our connection in unbelievable, but in the back of my head I'm like... Is this real...? Like, am I the rebound? 
I really don't FEEL like it at all, it's just when I think about it, I'm like... Am I missing something? 
Do I drill him with questions, or leave it be? I'm not worried about their relationship, it's just that it looks bad on paper, and also, I have no kids and no (alive) exes. 
What does a girl do!!! Any advice helps.