Under the kotatsu, the women's skirts were spread open, their panties fully exposed. Noticing this, I crawled underneath to closely admire their lingerie. Soon aroused, I decided to play a little prank—only to discover their panties were already wet. The kotatsu's warmth had made them sweat, their bodies melting with arousal. They tried resisting my teasing, but pleasure overpowered their will, and before long, right under the kotatsu in secret, I ended up having bold creampie sex with them—even while family members were nearby.