yes, the situation is much much clearer now.
wth were you thinking? she is already engaged with her bf. if you
are really her best friend, you shld really wish her all the best
and not hang around like a vulture, ready to swoop in at any
opportunity.
sorry if i sounded harsh. i can understand that you have feelings
for her but i can only say the timing just isnt right. if she is
single i would have strongly encouraged you since both of you are
the best of friends, even if kena rejected, your r/s also wouldnt
hit rock bottom. but sad to say, this isnt the case right
now.
i suggest you sit down and think through what you want to do. if
necessary, stay away from her for a while and cool down. if she
breaks up with her bf in the end, i would say congrats, fate has
given you a chance. else...