It depends on where you live. In many places, 16 is the age of consent, so anyone under 16 can't legally consent to sexual acts. Obviously you can date someone with kissing them and whatever, but it can still get messy. If parents find out they can launch an investigation.
Yeah, I think it's weird. Like, date someone your age if you're 16. You won't get in trouble, I don't think, but it's definitely not acceptable in my eyes. :/ Everyone has their own opinions though and they can do whatever they want.