This woman is my SO's best friends girlfriend. We went on a few double dates (horrid, they fought and she was awful to her boyfriend and flirted with my boyfriend) I found out she was flirting over text with my boyfriend (he didn't reciprocate and showed me because he was weirded out) I decided to be honest with her and messaged her on Facebook saying as nicely as I could (I put herself in my shoes and tried to be the bigger person which was hard because it's not okay what she's doing) I said I was uncomfortable with her texting my boyfriend, could she please not. She blew up on me and said all she wanted was friends (hello, I was on her Facebook and was so nice to her on our double dates she could have messaged me to be friends) I ignored her message and her friends are friend requesting me on Facebook and I keep blocking them. She's 21 but I'm really pissed off at how immature this is. What would you do and how would you handle this? I'm so mad!