Tell all my friend, get it off your chest, i know its what i should do, its just building up the courage which is the main problem, dont bottle it up mate.
I've talked to my friends and they said I would really be a d*** if i intended to get into the lives between her and her bf. Still you think I should tell her my feelings anyway?
I disagree with Markus for once. As a general rule, don't do things you wouldn't want people to do to you. If you would be happy if guys told your long distance gf they really fancied her, and tried to persuade her to get with them and dump you or cheat on you, then go ahead. Otherwise you should already know the answer to this.
don't confess. she's taken, and although honesty isn't a bad policy, it might not be best for this situation, as far as her boyfriend or even she could be concened.
Definitely don't tell her. If you care about her then be her friend, don't make a move on her and put her in that position. Maybe one day things will change, but for now put it to the back of your mind - she's taken!