Bathing with a lustful sister-in-law

Today is a day off so this guy stays home all day watching TV and playing games. Now my younger brother is on a business trip, so there are only Hibiki's sister-in-law and me in the house. As soon as I lie down in the bathtub, Hibiki comes back from shopping at the supermarket. Because he forgot to close the bathroom door, suddenly his sister-in-law came in and saw his huge cock, she began to crave it. Hibiki said that she wanted to bathe with her husband, and then he couldn't say no to such a beautiful girl.