The girl I fancy just asked me out. But my best friend (who has been out with her before) advises me to say no. What do I do

If you fancy her then how can you say no but I'm guessing she's not going to want to go out with you in secret. Go out with her just take your friends advice on board and see for yourself if she is like they say.

Ask your friend why you shouldn't incase she's like a nutter,I mean he dated her he should know

just say yeah if u like her and she likes u then y not go out insecurely I hahave befor

haha I ha I meant in secret

Go with what you feel don't let other ppl stand in ur way