Female friend avoiding me, why?

Anonymous
I have a female colleague(unmarried) say A,she has become my friend from the past 7-8 months.In early days I was the first person to approach her and helped her in technical (Software) matter.She became close to me and chatted for few months.Many times she praised me for my help and trusted completely.I thought I got a good female friend with whom I can share my feelings.Then another male colleague say Z(Married & have a child) came into her life.My friend A's home comes on the same way where Z's home is.She started to go with him daily on his bike..I had no problem at all,as I'm very broadminded person.I behaved with them casually.We go for hotels and cafes together.Once when we 3 were going for outing,she chosen Z's bike over me to go there.She went with him.That really hurt me a lot.It was like she doesn't have trust on me.Then I told this to her in next day.She told me she was sorry for that and she didn't mean anything.Later she started to move away from me.now she is attracted to Z.I can see her flirting with him and always looks at him while we were talking.She is now avoiding me.I thought she would become my good friend.Now I feel I'm loosing her.Should I talk to her about it? and solve this issue.Does she takes it positively?. This (Talking much with Z )will give her a bad name @ office.I want to tell her about it but how?
Female friend avoiding me, why?
2 Opinion