Will you feel upset when your ex-girlfriend is walking with another guy there?

Well, isn't it obvious that it's jealousy. But jealousy is not necessairly bad. It doesn't have to mean that you're possessive and whatever else they say. It can also mean you really like that person and care. Imagine if you felt nothing when seeing her with another guy, wouldn't that be worse?

Hmm, I think so, it IS jealousy. It's a very difficult thing to have, a very bad place to be in. It just might mean you still have feelings for your ex-gf and that you're not totally over her. It's nothing bad, nothing too serious, it's but normal for people to feel that way. What Eisenherz said was true, it would be better you feeling jealous than not feeling anything toward that incident at all which would mean you do not have any feelings for her anymore. But still it depends on you if you really wanted to move on and were very intent on doing so, not feeling jealous would be fine. Besides, you've already broken up and talking about having the right to each others' lives is out of the question now. Best be happy for her yet keep the good memories with you. Love can never be unlearned, it just might take another form with time.

yah it's jealousy. it's a way of having difficulties in accepting the fact that she already replaced you. hmmm... so far i haven't experience being upset or anything whenever i saw my exes together with their recent girlfriends. maybe because i'm very much open of the fact that without me, they can still find somebody else who can make them happy.