Arisu isn't exactly happy about this, but the feeling of debt is a strong one for good hearted people. MC is working on "saving" her and right now she's fighting some orcs. She's also feeling guilty and wondering if MC is coming for revenge. I assume the way that it will be resolved is either Shiba forcibly takes Arisu's first time, and MC "washes it away" so to speak, or he saves her and takes it himself. Of course, he already did, but that was in the level up area, not IRL. We'll have to wait and see.