person A: My sister took my best friend to the movie instead of me_comma_ I was really sad. 
person B: That would make me sad too.  Was there any reason she took your friend and not you?
person A: She was upset with me so to get back at me she did that.
person B: Lol_comma_ well thats rude! Hopefully you guys are better now!  Little grudges like that stink_comma_ I like to just put them behind me and move on.
person A: I try to make peace with her but she is always angry so I let it be.