Huge relationship mess... help.. ladies and gentlemen??? please...?

Ok I f*ck up bad today... long story really short... I made out with a guys girlfriend... (i only kinda know him.. never liked him)... as it happened my roommate walked in (hes kinda friends with the guy)... and he left immediately... i think she actually told her bf what happened and he broke up with her (she mentioned a while ago how their whole thing had been sour for like a year at least... or just no spark)... and so shes just pissed at herself and the world as far as i can tell... and i assume hes pissed.. and my roommate was put in a really awkward situation...



i apologized to my roommate... and he said i should definitely apologize to the guy cause hes the one who really got f*cked... and i apologized to the girl...



i feel like a complete douchebag... because what i did was very... ive never did anything like this in my life.. i had never even kissed a girl an im 19...



(btw she was really digging on me... i just gave her a regular kiss and she kissed back with tongue... thats no way to excuse my actions)...



whats the best way to apologize to the guy? (we live in dorms.. he happens to live on the same floor... not to far from me... ugh....) he deserves a apology and i am truly sorry.. (btw ppl keep asking if he could beat me up... no... but i deserve it..)



should i apologize face to face? or like a legit hand written note explaining how im sorry.. and that im a complete douche??



And what about the girl now?... its awful to just ignore her.. but its awful to actually take anything further because of everything...



Thank you.... and im sorry that this kinda **** happens... never thought id do something like this... :(Huge relationship mess... help.. ladies and gentlemen??? please...?
don't feel that bad!...it happens to everyone.....n if u hadn't even kissed until 19 ..u can't be that bad of a guy ( my first kiss was at 12 )..anyways so yes i think you should write a letter to the bf..saying you are sorry ..because if you do it in person there might be a fight.............n tell the girl that u are very sorry but you guys can't be anything !!.......Huge relationship mess... help.. ladies and gentlemen??? please...?
You got to make things right with her old man. He gets a free shot. That will solve your problem. Take a punch to the gut
well why dont the 2 of you go togather and forget about him **** happens it seems like the 2 of you like each other or the 2 of you would not be kissing each other
write him a note and throw it under his dorm room and run. then tell the girl that your sorry but tell her if your still intrested you can take a go
Well at least you are man enough to own up to your mistake.(She was to blame also) but you are the one to blame for lighting the fuse.So the best way to try to put the fire out is to apologize to the guy and hope he doesn't knock your head off and if he does just pick it up and make sure you position it right on your shoulders this time as you don't want to make that mistake again.Valuable lesson learned ,good luck to you