Thank you so much for your replies and support. I agree with you and will stick to my no and talk about why with her in hope that she'll understand something of my reasoning. Its a reality that a 21yr old will want something more from her after taking her out to dinner but as she has little experience in this arena I think I want to encourage her to come home after the romance and get used to dating rather than making it easy for her (and him). He does know her age as he is the son of a teacher at her school and used to attend the school himself. I've only met him once and he seemed nice enough although my older daughter (18) thinks he's a 'player' and not keen on him for her sister. How protective I feel!

Debra