<human>: I've known her for quite some time now (a few years). We work together on the weekends, but that will end in the end of this year. Past months we've been getting increasingly flirty. Peaks during work, days after work we text and this repeats itself every week.

 Lately I'm feeling like I'm finally making progress with her, and I think that something could definitely happen if the barrier of working together disappears. 

But the thing: she's been texting with a guy for some time now. He has a girlfriend and apparently sais he wants to break up with her but doesn't dare too. The girl I like thinks he's good looking, and from what she tells me more girls think so too. Maybe she tells me to make me jealous, I don't know. 

But I want to warn her. From what I've heard he's a dick. He's constantly bragging about how he's approached by this many girls in a club. He explains it in a way that to me comes over as really respect less. As someone who has a girlfriend I think he's a dick to that girlfriend. I've had a friend like that, and I know that he will do that to every girl just as easily, leaving the girl behind hurt.

Thing is: I don't think the girl sees that. I want to warn her that if he breaks up with his girlfriend for her, that he will just as easily break up with her for someone else. She's really good looking (well I think so, but some think differently) but can be so naïve sometimes. She doesn't deserve to get hurt like that, and I want to warn her before it happens.

I'm just afraid that it will make it look like I'm just trying to make that guy bad looking for my own gains. Which isn't my motivation behind it. I just want to pass on things I've learned in my live. Is this okay to tell her? And how to tell her that?

Can you condense the text into three sentences or less?
<bot>: girl I like, likes a guy who can't really be trusted. But she doesn't see that. Is it okay to warn her about it?