Guys and Girls: How do you react when you accidentally meet your ex?

Do you say a quick hi, or make a ''hi-facial-expression'' or do you just pretend you don't know that person?

I believe it directly depends on why the relationship ended, how long time ago, and how long the relationship lasted.

I'm asking it, because I'm really surprised with the fact that I randomly met my ex boyfriend of 4 years today, and he just pretended he didn't know me?

He was alone, and so was I. We broke up about 1 year and 2 months ago because he cheated on me and I found out. Since that happened, we lost contact but never had a bad tention between us.

Even though he didn't treat me well by cheating on me, I forgave him and never said any bad things about him..well maybe to my family, and that's all.

I think he behaved really childish, there was no need to do that, I was really surprised, because he's definitely not a shy person, and he supposed should to be mature since he's 29.

I have a boyfriend now that is perfect, so at the same time that I wonder why would any guy behave like this, I also think ''I don't even believe that one day I loved him, so why should I care if he behave like this, it's actually funny''... :D lol But then I remembered that I already saw this kind of attitude happening with my friends...and I think it's really childish and nonsense.

I mean it's not even a waste of time, it's to be polite and have manners.

So, is this kind of attitude really that common? How do you behave when you accidentally meet your ex? Do you ignore him/her? And why is that?

Thanks for answering.
I pretend I don't know him/her.
I'll say hi if I accidentally my ex is near/in front of me.
Select gender and age to cast your vote:
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''l'll say hi if I accidentally meet my ex or he/she is near/in front of me.''--> SORRY, confused 2nd option on the Poll.
Guys and Girls: How do you react when you accidentally meet your ex?
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