thats adorable that you guys were each other's prom date!
thats a really big favor, but if you hooked up once and said I love you.
than that is where you went wrong because you were abusing it, oblivious,
and young so just hope he didn't take it to heart. but yes you have to take
your friendship into consideration thinking if it is worth jeapordizing.
because if you make a relationship out of a friendship, things would
never be the same unless some miracles happen that you guys
can be friends with no strings attached. which is impossibe
because you guys have had history. but you should ask him
in a discreet way for his opinion of you guys being a couple
and if its a positive answer then that should help you
but don't rush into anything.