The ending of chapter 6 either implies mc’s is the biggest she’s seen or it is the first she’s seen.
A line in this chapter 31 of “I’ve also lived for a long time, but… This was the best I’ve ever felt” either means mc is the best sexual encounter she’s had or out of any moment she’s experienced, being with mc has been the greatest
Add to that the fact that she was in intense heat and the art lines mix sweat: there may have been virgin blood or perhaps none at all.