I think the language was very appropriate in this scene, because right after Neal says it, he has a moment of, “Ooops,” which shows that he’s not used to being around kids and has much to learn if he wants to be a dad. I’m not usually around kids, and I typically swear as part of my everyday language without giving it a second thought, so sometimes when I’m around my friends’ kids, one slips out, and I have a moment just like Neal did in that scene. Was a very real moment and a nice little touch of character development for Neal IMO.