I bet the boy isn’t really the baby’s daddy - looking at the picture of him, there’s no way he’s gone through puberty yet, as opposed to the kid who was the father of the twins in the earlier post. I wouldn’t be surprised at all if the babymama actually was messing around with another guy and just didn’t want to admit to cheating when she ended up pregnant.
There's no such thing as "cheating" when people aren't married. There's just, "I'm also screwing some other guy/girl. Deal with it."