Is it okay to go after an employee at my dad's company?

There is this guy that works for the company my dad owns and I really like him and have for about six months. He only works during the summer when he's on break from school though so he's not around all the time. He is a really sweet nice guy and I thought he liked me at the end of the summer but then he left and I went back to school. First of all, is it okay to pursue someone that works for your dad? Also, he invited to go to a party that his fraternity is putting on at his college that is almost 10 hours away...I was planning on visiting a friend that weekend that was a few hours away from him so do you think it is okay for me to go to his party or is it going to be weird since he will know I drove 10 hours just to see him for a few hours at a party. Thanks for any advice you can give me!