Why would your ex not be happy for you to finally find someone else when he has had a girlfriend for a year?
==A guy's take== I think it's important to look at why you guys are exes in the first place. It sounds to me like he has some possessiveness/control issues; he may not be very good at letting go even after a year of being with someone else. Maybe he wants to have his cake and eat it too. If he was in any way controlling or abusive with you or serially cheating on you I don't give his current g/f good odds either...I don't think that in general people change very much - they may be able to alter their behaviors, sometimes forever, but they most often continue in the same general thought and behavior patterns unless they are very motivated. You may want to think about the reasons why the reaction of your ex is important to you. It may be better if you both move on as much as you can - and just accept that you have separate lives. He sounds immature and egotistical. He was happy you didnt have someone while he did, jealousy could be the reason too. Guys love to think they are legends in their own minds and now that he realizes you are not "alone" and getting some too, his ego is hit. Too bad, so sad for him. If he cared how you felt he would have not showed any reaction to whether you had someone or not, just been there as a friend.
How do you get someone to stop being jealous of your relationship with someone else so that you can kiss your Gilrfriend without the jealous person getting upset?
Will you introduce someone young and beautiful to be the girlfriend to someone you love but you know it's impossible between you two?
Well an obvious answer would be that they would tell you, but things are always that ideal. I would pay close attention to their actions, do they make an effort to make you happy? Would they be okay with you being with someone else if it made you ultimately happy? It's not a straight forward answer, but love isn't straight forward. depends on what sex they are make your move but if he already has…