best mate is some one who can really understand your problem and can help you to solve the problem. not just some who you hang around with couple of days. he/she should be able to help you to solve any problem. not run away when you have a problem.
I always just walk up to them and ask what are you doing this weekend and if you just want to hang out. Or if your really shy "like me" just get someone to ask him or her out.
The first step is to find out why they hate you. They could possibly not be as mad at you as you think. If they are, it could possibly something simple that you could easily straighten out.
Once...
You can be a good friend to your best mate, choose your sexual partners carefully and don't include your best mate in that group. Sexual partners are much easier to find than a best mate.