How do I get y mom to see that my best friend is just a friend?

First you could start off by telling her that you have better things to do than to disrespect your body by letting some guy take advantage of you. She is your mom and is just worried about you. Another good idea is to have your friend come over and talk to your mom so she can see for herself what kind of boy he is. Right now you think that your mom doesn't understand and that she doesn't know what she is talking about and all that but the problem is is that your mom was your age at one time and over the years has seen what happens to some girls when they are overly trusting in some guys. She sees that this friend and you are getting to that age when things start to happen. This is why it is a good idea for your friend to spend some time at your house so your mom will feel more comfortable with him and see that his intentions are all good.