There's this girl..

[z†cĸα]

If you ever talk to her just say you can be friends. And hope she understands. If she doesn't she might get all the girls against you what wouldn't be really cool.

[Hollow™]

How do you think she overweight? Is she really fat? Talk to her and tell her that you only see her as a friend. You shouldn't ignore her if she did something to help you in return. A girl doesn't like to be ignored.

[Peter L]

Yeah, just tell her how you feel, she might think you like her if you keep talking to her ;)

Come on man learn to read the thread. Stop spamming for your damn support feather.

[Apex]

The best thing you could do would be to just hook him up for example at school and tell her how the things really are. Show her that you have no interest as the things will get worst if you just keep ignoring her.

[The Anarchist]

Let her down easy, if she flirts, tell her you just want to be friends and you're not looking for a relationship. Don't make it sound anything like it's because of her weight though, since that could be bad.