Maybe the reason he told you is because he is trying to test your boundaries and see how far you are willing to go.

Maybe he is hoping to have a secret affair with you, where his current gf and baby never find out about it.

If he starts confiding in you that he is in a sexless relationship, beware.

If he starts getting into conversations with you about what he would like to do with you, beware.

Perhaps he picked up a signal from you that he perceived to be a flirtation.

Then again, maybe none of this is true.

You say you've known him for awhile, but how well do you REALLY know him? Hang out everyday? Text friends?