Is AUTHOR wrong in the post ? POST : I am living abroad and I have a long distance relationship with my gf. I use twitter actively and sometimes I talk with people with a friendly behavior. I don't have much friends in here to go out casually. 

Last semester there was this girl I know from my home city, i barely knew her (we've met a few times) and she was doing exchange semester in another country. I learned that on twitter and asked her about her exchange like when did she go or how did she feel. Sometimes I talk with people or make jokes with people by mentions.

My girlfriend thinks it is not normal, asks me why do I need to talk with people casually.

AITA for talking people with a friendly on social media and find it is okay when you're in a relationship?