Crisis date 2 a dance?

so ryan asked me at the beggining of the year to go wit him actually a promise...anyways like after 2 weeks he like already had forgotten and he started dating this girl ariel and i started dating tate so we kind of were not going wit each other anymore and ryan also put me through a lot of crap.. then we both ended up breakig up with r bf and gf ... so since i wuz a cheerleader last year were the ones who have 2 organize it and stuff so i wuz plannin to go with my friends like altogether then today ryan asked me 2 the dance again.......i really don't know and even though he asked me today well right after school he starts puttin his arm around this girl amber and flirting wit her i mean wat is up that crap........plz tell me if i should go wit him....thnx oh and all of my other friends dont hav dates and i dont want to go wit him if my best friend doesnt hav a date but i dont know ryan is so nice 2 me and he is really cut so plz tell me if should go with him!!!! thnx %26lt;3 %26lt;3