Matsuzou and Matsuyo - S2.E4

Noticing Matsuzou acting strangely, the siblings discover that he is worried that there's not enough spark in his marriage with Matsuyo. Feeling he should return to a more innocent time, the boys give Matsuzou a masterlcass in being a virgin, albeit with no success. Matsuzou inevitably resorts to getting a love potion from Dekapan, but ultimately decides against using it, managing to sort things out with Matsuyo by himself.