You know, I kind of figured the loli brat wouldn't succumb to MC's charms even after a couple days of aphrodisiac-induced non-stop sex. Whatever beef/trauma she had with men in the past had made her put up a near impenetrable wall with spikes that will stab any men that tries to get close. MC was lucky to find a weak enough spot to break in, but the hole is small and can be repaired quickly. The thing with repairs, however, is that the product will never be as good as it was when made the first time.
MC may have lost this 'game', but it was only one loss, and he said he's not used to losing many games, so this isn't the first loss in anything he's ever experienced. He's not the kind of guy that sulks after a loss, however. He used that loss as experience, learned from it, and will attempt to try again with a different strategy, especially now that he's found at least one weak point in his opponent.
Then again, I wouldn't be surprised if he doesn't bother trying again with the loli brat. I wouldn't blame him. She's just too big of a pain in the ass to deal with.