A Threesome between a Brother And Sister and an unrelated third party. It may not be necessarily Incest as the siblings may only focus on the unrelated party instead of each other.
Examples
See also
- Shimaidon (threesome with two sisters)
- Kyoudaidon (threesome with two brothers)
- Mother And Son Threesome
- Group Incest
- Bisexual Female
- Bisexual Male
- Boy And Girl Sandwich