Greets ,

I`m in a very confusing situation , and I don`t know what should I do , how should I act ,
what is appropriate and what is not .

So there is this girl , let`s call her Lissa , which I met around 5 years ago .
At first we really did not pay too much attention to each other, but I always found her lovely .

This changed couple of months ago , we got a bit closer , and now we seem to get more closer
and personal each day passes , we talk for couple of hours a day .

After each day passes I seem to think - "why have I not looked at this path earlier ?" .

Two things bother me though -
1. A friend of mine is , let us say "chasing" her for over a year now , though they seem to go nowhere ,
she said to me she wont like anything with him .
So - I don`t know if it is ok for me to try something with , or is it just very mean ?

2. I have no idea how she feels , or rather , if she feels anything whatsoever to me .
There are no visible signs , I believe , though some did say it seems like she likes me .

What do you think I should do ?
Should I "sacrifice" this friendship ?
Surely , if she`ll agree to go out with me , my friend would not wish to speak to me further ,
as she is on his mind for over a year .
If she says no , then my friendship with her would probably take a twist, as it will be awkward .