Why did my friend fall out with me?

iam a male and i have been best friends with a female since we where early teenagers at one point we got closer than friends as in the odd kiss (when we where teenagers ) .now 25 years on we have never lost that friendship so much so when she drinks a little too much she can be a bit loose with her lips and has told me that shes in love with me several times. the next day nothing is mentioned and we get on with our lifes as nothing was ever said as i put it down to the alcohol. we are both in long term happy marriages .sometimes we can argue about our familys and friends and at one time she slapped me when drunk and for the next two weeks cried and tells me that its the worst thing she has ever done.i have been there all her life for her and know everything about her and i have always been the one she confides in and helped her pick up the pieces.well a few weeks ago her brother started a fight with a friend in a restaurant and threw a gl of water over him for no reason in front of us.so the following week we had a few drinks too many and i told her that her brother was a total *** hole at times well she stormed out and then told all our friends and family that she hates me and told them that i called her brother an *** hole and is constantly bitching about me to them .she has totally fallen out with me .i dont understand when we have slagged both our familys over the years and accepted it like brother and sister.i know she is having problems with her husband but why has she totally fallen out with me.all our friends have told her that she has went over the top with this .WHY ME . AND WHY BETRAY ME TO OUR FRIENDS AND KEEPING IT GOING