Is it ok for a 14-year-old and a 17-year-old to be going out when they think it might lead somewhere?

Its definitely not okay. The 17 year old can and will be charged with statutory rape, and if the parents aren't involved in this at all, another big mistake. Parents can get the 17 year old on a restraining order or arrested. Ask the 14 year olds parents this, not strangers online.