Year/Grade 8 girls always haring me?

When they come up to me they always talk to me,(I'm 13 by the way, in year/grade 7) but when they talk to me, they always laugh when I'm talking to them, for instance when I was playing Football,(AFL), I was in the goalsquare, one of the girls asked me out of nowhere, and I said to her "no, because if you want to go out with me I need to get to know you more", but then she said, "Why don't you ask me out now?", then she started to cry, but one of my friends said she was pretending to cry, are they play on me or somthing?