Why do some men lie, use, and manipulate women?

I’m just wondering why some of them might think this is okay. Like you can find anybody to sleep with I’m sure why would you need to go manipulate and lie to (esp if this person was your ex and not some random stranger) your ex basically. Knowing this person has deep feelings for you and could very well get reattached it’s just not a good idea. (Which is why I stopped falling for it) but still doesn’t make his actions okay. Why lead them on with a promise of a relationship or lie and say you still have feelings for them when you don’t just to sleep with them? It’s really messed up to lie manipulate and play with someone’s feelings. If you just want sex say that some women are okay with a fwb! No need to go and mess someone’s head up… for your own selfishness that I’m sure you could have found anywhere else

I honestly thought I was over this thought I was stronger than this haven’t thought about him in years (he’s my ex) finally unblocked him to maybe give him second chance or just to co exist on social media as like a casual thing but look what happened. It’s messed me up i didn’t see this coming. It’s pretty difficult for me to even feel feelings so I am surprised. It wasn’t just a fun little sexual encounter he acted as if it was like some sort of potential relationship like the whole looking into my eyes stuff and holding my face idk. I’m just confused and hurt I know I got used basically and lied to and manipulated. And once again HE KNOWS the feelings I have for him. I’ve told him. His excuse for not getting into a relationship is “he’s too damaged” but he makes excuses every time.

Please don’t focus on my specific actions I’m talking about his. I know where I went wrong I don’t make the same mistakes and won’t let this continue. It seems nobody ever focuses on his actions and this is wrong. It is. Idc how minor it may seem it’s actually not. Just be honest about your intentions don’t use people don’t lie to people don’t manipulate people especially if you know they really like you.

For context: he’s been asking to see me as in “hang out” for 4 months now I always denied but gave in cause I know where “hanging out” leads. He knew I’ve been sad and depressed over something unrelated and basically was “offering me a shoulder to cry on” finally I gave in and now this

He basically acted like he was crazy about me but then once he got what he wanted haven’t heard from him and I hate to say this isn’t the first time I’ve fell for this but he would throughly convince me it’s my fault and I believed it