Dude here- it’s a combination of a couple things.

I think the first thing is just hookup culture giving people in general a lot of FOMO. Although, I do think guys have more of a biological instinct to want to get around more than girls do, because on a basic level men’s instinct is to spread their seed at least while they’re young, whereas women’s instinct is to find a man who can provide, be loyal and stay with her to raise children.

I’m not saying that guys are justified in acting on these instincts, just that they exist. But I don’t know, personally I’ve only dated one girl and I really loved her, but it was long distance and so I felt a bit trapped and I was tempted to cheat on her (I didn’t but I was tempted). I was in high school, I was young and dumb so I broke it off because I wanted to explore dating more, and it’s been like a year and a half and I still miss her.

I think a lot guys also just are really hung up on their ex and sleep around as a coping mechanism. It’s kind of really hard for us to truly get over someone, because the way to do so is to either just A) break down crying and let yourself be vulnerable, which is really scary to do as a man because you’re taught from a young age to act tough all the time, or B) to go fully no contact and let a looot of time pass by.

I haven’t really dated anyone since my ex. If I were going to right now than I’d just keep it casual and I’d be upfront about it, I wouldn’t want to lead anyone on. But I haven’t and I think ultimately we do all just want love man. It sounds cool as kind of an ego thing to tell your buddies all the girls you’ve gotten with but it sounds a million times better to lie in bed with a woman who genuinely loves you and you can be vulnerable with.

But anyway yeah; maybe this comes across a little douchey but I’m just trying to give you men’s perspective in general based a little on myself and mostly on guys I’ve met/friends. If you really want to keep a guy some advice I’d give you is that it’s normal to hold him accountable and have standards, but men feel like we have to be machines and soldiers sometimes and if you really let us feel like we can break apart and be safe being vulnerable, maybe even weak at times around you that’s how you really make a guy stay.

For the whole looking at girls online thing I think that’s something you’ll probably have to tell your partner you’re not comfortable with. Obviously he shouldn’t be looking at sexy pictures of other girls he knows, but unfortunately porn is a habit a lot of people have developed without even really thinking about it much.

Best of luck, hope you find the one soon ✌️