Is it normal for him to chat up other girls?
Me and my ex were together for 5 years, and then broke up two years ago. I was the one who initiated the split, as I felt too young for the level of commitment that we were at (he wanted to get married). Since then, we have continued hanging out together just as much as before (when I'm home from Uni) and sleeping together, but when I'm at University we aren't together. He's always wanted to get back with me, and he hasn't slept with anyone else since we split, although I have (when I'm at University). This might seem an unconventional relationship, but it's worked for us, although he does get angry and jealous sometimes. We'd always kind of assumed that we'd get back together after Uni, well, I graduated a few months ago and since I've been home we've been sleeping together and having a really great time. We hadn't discussed whether we were together exclusively.
Then, last week, he asked me to promise to only be with him this summer, until I go away again to start an MA at a new university only half an hour away from him. He asked me to promise to be exclusive to him until then, with the suggestion being that we would get together again properly and possibly marry when I am settled at my new uni, and I readily agreed.
So yesterday I'm at his house on his computer while he's at work, and this facebook message from a girl pops up (he'd left himself logged in). Apparently he'd chatted her up on the train the week before and then FB messaged her and she was responding to her message. I checked the dates of the messages, and he'd literally taken me to the train station, put me on a train, kissed me and told me that he loved me, got onto his train, and started chatting up some other girl. I'm not exaggerating, I saw him get on the train next to mine and his train journey is only ten minutes long! Meaning he must have started hitting on her immediately. 3 days after he made me promise to be exclusive to him.
Am I right to be pissed off about this? is it normal for him to do this after saying he only loves me and desperately wants me back and saying that we are together this summer?