Rape wouldn't be allowed because a child under the age of 18 legally cannot consent to anyone over the age of 18. Period. It is impossible under the law for a 19+yr old to have legal sex with a 17 yr old. That's why it's called statutory rape.I will admit I making this into a bit of an exercise. I don't disagree with you, but the point is there's a veritable panorama of interpretations of what is allowable based on that statute. I suspect it was written to allow parents benefit of the doubt when it came to reasonable physical punishment, but I would go so far as to call the wording reckless with what it allows.
Anyway, it is Texas, and they're all for freedom to do whatever you want (unless it's homosexual). But I can see why their law is so lax compared to a lot of other states.
In Oklahoma, you can't starve or torture a child either. But you can spank, switch, paddle, etc. your child for discipline. It's not specifically listed, but I'd imagine hitting with a belt would also qualify as legal in OK. The interesting thing is that a school teacher and other adults can discipline your child too with the same force. And if they do it to your child for discipline purposes, you can't bring them up on charges.