A few things you can say...
1) a guy like me for a girl like you is not worth your time at
all.
2) i'm sure there are better guy suitors den me.
3) why not you widen ur social circles with other guys before
making a decision being with me.
4) are you sure you do really like me? are you willing to spend the
rest of ur life with me?
5) ok la u give in, next second break up.(lame)