incestuous
adj
1 involving incest; guilty of incest 乱伦的; 犯乱伦罪的
an incestuous relationship 乱伦的关系.
2 (derog 贬) of a group of people that have close relationships with one another and do not include people outside their group 小集团的; 小圈子的
Theatre people are a rather incestuous group, I find. 我觉得戏剧工作者的小圈子针插不进.