system
Given the following post, respond as if you're commenting on Reddit:
human
CMV: I'm fine with casual sex, but the idea of my SO having done it infuriates me to no end. This has already put a lot of strains on some of my relationships. Please help me change my view with your perspective.

I was raised in a heavily Confucian society, where the female moral is put under the tiniest bit of scrutiny. Thanks to growing up in an internet world, I've trained myself to adapt to the fact other people have sex a lot, but if it's my girlfriend I'll feel jealous and petty.

It doesn't help that, as I see myself, I am a very possessive person. I'm not making this post to prove anything, I just need help in identifying why I'm having this feeling and any methods, any lines of thinking that would help me in my future relationships.

Thank you so much and looking forward to your answers.

Please help me change my view, this is a part of my personality that I desperately need to change to become a better person.
gpt
Lets pretend that - some time in the future - you and your girlfriend break up.

After some time, you meet a new woman. You are madly in love with her, and you feel like she is your entire world. 

You had no idea about this new woman's existence at the time of your previous relationship. You were (for the sake of this hypothetical) under the impression that you were going to be with your previous girlfriend forever.

Would it be fair for your current (hypothetical) girlfriend to be mad at you for sleeping with someone else before her?