How would I dissuade my friend from dating a woman with a loose vagina?

Throwaway account for obvious reasons.<br><br>I’m a 20 y.o male.<br><br>My (20 y.o) friend has been talking to a girl (let’s call her Lisa). Lisa has been clearly interested in my friend, and she’s always flirting with him when we all hang out together. So my friend recently made a move and asked Lisa out, and to no surprise she said yes.<br><br>I’ve known this girl for a little more than a year now, and in that time she’s been in relationships with 4 different guys. And from what I know of her, she seems to move on from relationship to relationship without really taking any time to herself in between. It appears she’s never single for too long.<br><br>So I’m worried for my friend. Seeing how quick she jumps into relationships, I’m afraid she’s gonna end up using/hurting him.<br><br>What’s my best approach here? I don’t want to seem like I’m talking down on Lisa, which may make things awkward for our friendship going forward. But I feel like this knowledge may be important for my friend to know.<br><br>TLDR: Friend blinded by love, Lisa jumps from one man to another like it’s a competition. How do I tell my friend?<br><br>Edit: some context - she’s definitely slept with all 4 of the guys she’s been with, and she’s constantly flirting with many other men too. She’s so outgoing and flirts so much that it’s almost like a reflex when she talks to a guy.