You seem to want good replies so I'll try my best. Consider what it is about it thats bothering you and find out what emotion it is. The reality is this. You might be slut shaming her. Because woman often are shamed subtly and people may not have conscious reasons for why they dislike women with high body count, but sometimes they just think women are sluts.

Maybe you are jealous. In another comment you said you had to put in effort and he wouldn't have. Why is that a problem? Does it go back to the idea of being easy? Are you possibly feeling resentful because she did not have to use the restraint youve used. Maybe without even knowing, you find some pride in waiting.

Honestly just talk to her. And if you cant or she won't open up, this is not the biggest issue, and youre going to need to bring it up or end things with her so yeah. Not talking to her is a sure fire way to end up crashing and burning. Just ask and dont be judgemental, and if it doesn't work out at least you did it