The asker has asked about dating, not about sex.
That being said: bshaw, don't be dumb. A 32 year old who wants to "date" a 17 year old has some serious issues in his or her life. Avoid it.
As for legality, I'm not sure that any state has either defined "dating" or has made laws about it.
But if you are talking about sex, then that may be a different story Google your state laws.

