PLEASE READ I REALLY NEED HELP XX

ok, so i like this boy and everyone says he likes me to. yestreday my very annoying sister walked up to him and said: my sister loves you go out with her. Obviously i had ran away. Later that night i asked my sister what he said and she crossed her heart and hoped to die and she told me this. she asked him if he likes me and he said "i love her" and then she said would u go out with her he said "cause i would" then she asked him why doesnt he go out with me he said "cause she loves bobby". Bobby is the boy i likes best friend and i absolutly hate him so to wind me up my best friends sister asked bobby out for me a few weeks ago and he said yes. Bobby knows i hate him, but the boy i like thinks i like bobby cause i go all cringy around bobby and start giggling but i absoluty hate bobby. please help what shall i do i dont wether im going out with the boy i like or not. please somebody give me some advice i realy need some xx