Is it betraying my friend if....?

so my friend met a new guy at work who she kinda fell for. They hung out a few times and even though shes very innocent, she tried to hook up with him the first day they hung out. she met some of his friends, and one in particular she thought would be a perfect match for me. so right before she introduced us, she pulled me aside and said that she really didn't want me to flirt with her crush and that she would be heartbroken if her crush started getting feelings for me over her. i was just like wtf? because its not like guys are all over me all the time and im not even that big of a flirt. so i met the boys and we all got along really well. i felt chemistry with the match and i was friendly with her crush. but as i hung out with them more, the roles seemed to switch. actually, i flat out fell for my friend's crush. and come to find out, the other guy is a good friend's ex! so me and my friend's crush started seeing each other literally almost everyday if not definitely talking on a daily basis. we started hooking up as well and it turns out this guy has really fallen for me too. he even told my friend that he wasnt felling her and that they should just be friends. this guy and i have had a lot of talks about it and hes never really been that into her, he just didnt know how to let her down easy. she was too innocent and looks kinda like a little kid. :[ but not were at the point in our relationship where both of us are looking for a relationship. and i dont know if i could do that to my friend or not. i dont fall for a lot of guys and my friend knows this. would it be wrong to take this any farther?