One or more of the heroines is the protagonist's sister-in-law. Sister-in-law refers to the sister of protagonist's wife, or the wife of protagonist's brother. In rare instances it may also define the relationship between people who marry siblings and refer to the wife of protagonist's spouse's sibling.
| Name | Similarity |
|---|---|
| Sister-in-law Role | 35% |
| Brother-in-law Role | 17% |
| Boobjob Engages in (Sexual) | 16% |
| Wife Role | 16% |
| Younger Sister Role | 14% |
| Infidelity Engages in | 14% |
| Doggy Style Subject of (Sexual) | 13% |
| Naked Apron Clothes | 13% |
| Quickie Fix Subject of (Sexual) | 13% |
| Skirt Clothes | 13% |
| Cowgirl Subject of (Sexual) | 13% |
| Standing Sex Subject of (Sexual) | 13% |
| Older Sister Role | 13% |
| Sixty-nine Engages in (Sexual) | 12% |
| Husband Role | 12% |
| Blowjob Engages in (Sexual) | 12% |
| Ponytail Hair | 12% |
| Sitting Sex Subject of (Sexual) | 12% |
| Miniskirt Clothes | 12% |
| Brown Hair | 11% |