Confusion

So I love it when my man leaves hickies on me, because who doesn’t love to look down at them and be like “where did that come from? 😏” but yesterday he tried leaving some on my chest like usual and they didn’t stay long. I know he knows how to leave hickies, he’s done it a thousand times before, but for some reason it didn’t stick. My breasts have also grown two cup sizes so I’m wondering if it’s something to do with my skin?? Or maybe he just wasn’t sucking hard enough 🤷🏻‍♀️