The art in here isn't too bad, though I'm not sure a homeless stoner would have perfect teeth.
The voice acting could use a lot of work. Both characters lack sincerity, or that aside, humor. It sounds like they're reading a script rather than speaking naturally. As I'm not a voice actor, I can't advise you much on how to do better, but a thing we writers and artists do a lot is leave our work alone for a few days before posting it, then we come back and look at it with a clear mind. We get into a rut when we're working on something, and we call that tunnel vision. Taking a break clears said tunnel vision.
Go back to your animation after a day or two and listen to your voice acting. If you're not convinced by it, chances are your viewers won't be, either.
Next, the logic could use some work. The stoner's advice doesn't make the slightest bit of sense and I'm not sure how young I'd have to be to believe it. Chances are, if I was young enough to believe the guy, I'd also have been too young to know what a C-section was. If the guy's that stoned, his logic probably wouldn't make sense anyway, but a kid almost certainly wouldn't believe anything he said, much less come to him for advice in the first place.
The ending wasn't surprising. The stoner demanding some kind of compensation was entirely predictable. I didn't see it coming, which is a good sign, but when I saw it, I wasn't surprised in the slightest. Generally, with twists, you want your viewers to say, "I can't believe I didn't see that coming" rather than "I didn't see that coming." Most writers know that, and I'm willing to bet you did too. However, I think something should be added to that. You want your viewers to say, "I can't believe I didn't see that coming!" with passion and with either a huge smile or tears starting to flow. With this animation, I barely raised an eyebrow.
The animation itself is smooth, but slow and obviously tweened. Characters don't gesture as would in real life and their movements are just off in nearly every way. For example, blinks should be super-fast. I shouldn't be able to see the frames of the eyelids going down or coming up. I should only be able to see they eyes fully open, fully closed, and fully open again.
The music, I have no comment on, as I don't think I'm experienced enough in how music works with other elements of animation to give you any worthwhile feedback.
Though I hate the star rating system and wish I could just give feedback without having to assign the degree to which I liked or disliked this animation to an abstract pseudo-numerical value, Newgrounds forces me to. You do show promise, and I'd like to see how you improve in the future. Just--don't pay much attention to the star ratings. They do nothing for you but make you feel bad when they're low and good when they're high.