How should i approach this?

i like this guy well he thinks i am pretty and what not but i am not his type idk y though...well i am kinds over that ...well today at our school we had this hear thing well this chick took his with out him knowing and but it on her chest and a rose in her clevage ......and now she is going to the dance i cant go because of my gpa=[ oh well right well he is going and i know i shouldnt care but he is the first guy to regect me and well i know he doesnt like her because his couzin told me but what if they dance together that can change every thing and well i dont want to lose to her because she is a skank for one and secoundly ugly and so how should i approach this with out letting him know that it got to me cause i dont really like him anymore i found a new guy to talk to but it still makes me mad if i were to lose to the ugly skank so help