No, you're not. You're only dating the dad. If the kid has a crush on you, that's fine, but as long as you are dad's girlfriend and the child's FRIEND-FRIEND, no problem.
I'm not worried about him getting a crush on me, I'm worried about him getting attached to me as a maternal figure.
Anyways, it doesn't matter because this relationship is doomed due to the fact that his father is a Type 4. Already the sickeningly familiar pattern is starting to emerge. Never, never again shall I date a man who self-identifies primarily as a musician, writer or artist.
"Tell me, what is it you plan to do with your one wild and precious life?" - Mary Oliver
