MAJOR HELP PLZ....girl trouble?

ok... my friend is taking his girl jess out to pizza and said i should bring 1 too. my friends girl suggested a girl then a sec later asked this girl for me.. i told her i wanted to ask out this girl megan... so i asked mag out and jess asked another girl. the other girl said she will go, but meg said that this girl should go instead....i really like meg...should i just get a date for the other girl?plz help how do i get meg to come? thank for reading.