He may not be too old. I'm 18 and my boyfriend is 21...but you need to check out if this relationship is even legal in your state. In some states, the age of consent is 16 or even higher. I would definitely be careful of that, since your boyfriend could get in trouble.Your friend is probably looking out for your best interests as well, but maybe she doesn't know the full story on this guy. If she hasn't had the opportunity to really get to know him, try to have them spend some time together.What do your parents think of him? If they can respect him, it may work out. They're also looking out for your best interests so take their opinions seriously.Ultimately, it's your decision what you do. Just keep in mind that people around you care about you, and if they're concerned about you dating this boy, you should think about why. Try to take a step back and analyze the situation as if you weren't the person involved. Good luck.Hope this helps.