If I see one more new engagement ring before the end of the year, I'm jumping off of a bridge.

Girl A and Boy A begin to fall in love. Around the same time, Boy A's best friend, Boy B, begins to fall in love love with Girl B. Girl A and Boy B discover they have a great connection and also become good friends. Over time, Girl A and Girl B become best friends. Girl A and Boy A's relationship holds out pretty well over the next few years, while Girl B and Boy B's relationship is very rocky and eventually Boy B cheats on Girl B and their relationship becomes on again/off again until they are finally done for good. Girl A and Girl B are still the best of friends, but Girl A's friendship with Boy B becomes a little complicated and distant. Words get said, feelings are exchanged, and in the end Girl A and Boy B conclude that they still care for each other as friends, even if things aren't the same as they used to be.

Girl A wakes up one morning to Boy B confessing his love to her through text messages. Girl A gently tells Boy B that she isn't upset, but doesn't share those feelings. Boy B asks girl A not to tell Girl B or Boy A. 

What does Girl A do?