I think you are taking everything he says at the face value and you shouldn't be. He could be lying. Here is a prime example where he could be lying:
rvce said:
reason for the break up he gave was he was getting married with another person and he hates it
If he ''hates it'' as you put it, why did he marry her? She can't force him to marry her, so apparently he wants to be with her.
I can see where you are coming from in terms of wanting to give him benefit of the doubt. But at least you can ask him regarding the details of what his ex did to ''force'' him to marry her, in order to see whether or not it is believable. And when you ask, don't take his answers at a face value either. Here are few examples of possible answers he can give, that would be VERY BAD answers:
1. Suppose he says that his ex threatened him to stop her friendship unless he marries her. In this case you should realize that no one would agree to marry simply to maintain friendship. What this shows is that he actually is still in love with her. If so, the thing he ''hates'' is that he had to choose between two women instead of maintaining love relationship with both. The latter is called cheating. In other words, he is a cheater and he hates the fact that they are not letting him cheat. Well in this case you don't have to try to make cheater feel better. Cheaters deserve what they get.
2. Suppose he says that she threatened to ruin his reputation against his friends/coworkers unles he marries her. In this case your next question should be what exactly did she threaten to tell them? At this point you have to remind yourself that marriage is life-long decision. So if the issue was him losing a job -- which he can replace few months later -- that is not a legitimate reason; if he claims that it is, he would probably be lying unless he talks about some high profile job in the government or something. In fact, the only possible way this could be a legitimate reason is if he committed a crime and she threatened to get him to jail for it. If that's indeed the case, then its his fault and you shouldn't be friends with a criminal.
3. He could tell you that he was forced to be with her because he is poor and she is financially better off than you. Not a good reason either. You can not buy love, so if someone was able to ''buy'' his love it means he never loved you to begin with.
Now of course there are a lot more examples of the possible reasons he could give. But you got the jist. Basically, try to analyze everything he says and get to the bottom of it, before you ever trust him.
rvce said:
and he wanted me to be in his life atleast as a friend
Yes, I am sure he wants you in his life as a friend -- if he didn't, he wouldn't be trying to persuade you to stay around.
But you have to realize that just because someone ''wants'' something, it doesn't make you obligated to give it to him. No one ''wants'' to take responsibility for their actions. But that is not a valid excuse to let them get away with everything.
rvce said:
he became all depressed and dramatic.
That is called emotional manipulation. Some people might pretend to be very depressed in order to get other people to do what they want. If you give in, they will see that it works, so they will do it more and more.
rvce said:
And why weren't you? The typical response to simple cheating is anger and breakup. Now he did something 100 times worse than cheating -- he actually MARRIED someone else and never told you about it until the deed was done. So you have every right to be upset and angry. The fact that you weren't probably shown him that you are naive which is why he decided that he can lie to you and emotionally manipulate you without you ever questoning him; this is what he is probably doing.
rvce said:
and later i help him out and i come to know he has married his ex girl friend. and he wants to be part of his life no matter what? and i don't know if i will be able to handle it because these days he is just giving me crap and saying it is my mistake for what he is turning out to be.and i can't tolerate when he is in problem. i want to be with him when things are not alright for him and till now i have been for him.
Once again, the fact that he ''wants'' something doesn't mean that you are obligated to give it to him. The fact is that it was his fault that he cheated on you (in fact, far more than cheated) so he should face the consequences of his actions.
P.S. Have you actually lived with him in the same place? If not, it is quite possible that his ''ex'' has never been an ''ex'' to begin with. He could have been with her all along and he simply lied to you they broke up -- until, of course, the marriage came. You should ask around people other than him to see what was really going on. If what I just said is true, then he doesn't deserve any of your friendship or sympathy.