HELP!! Major opinion needed

hi so i'm a junior in high school and i'm going to prom but my original thought for a date just got back surgery and so i'm not going to ask him anymore since he's in the hospital. but!!! i just ran into my best friend from middle school that i miss so much and haven't talked to since we don't go to the same school anymore and in middle school he took me to a lot of the dances. he has a girlfriend now and idk if she really likes me but i want to know if it would be weird if i asked him to prom with me as a friend, bc i miss him and never see him anymore? and if it's not weird, how do i ask without trying to sound like i'm getting at him?