Anal Intercourse
Our nature is to dislike anything unclean. Please ask Mufti Abu Layth for references. There are no narrations in my knowledge that make this act permissible.
﴿وَیَسۡـَٔلُونَكَ عَنِ ٱلۡمَحِیضِۖ قُلۡ هُوَ أَذࣰى فَٱعۡتَزِلُوا۟ ٱلنِّسَاۤءَ فِی ٱلۡمَحِیضِ وَلَا تَقۡرَبُوهُنَّ حَتَّىٰ یَطۡهُرۡنَۖ فَإِذَا تَطَهَّرۡنَ فَأۡتُوهُنَّ مِنۡ حَیۡثُ أَمَرَكُمُ ٱللَّهُۚ إِنَّ ٱللَّهَ یُحِبُّ ٱلتَّوَّ ٰ⁠بِینَ وَیُحِبُّ ٱلۡمُتَطَهِّرِینَ﴾ [البقرة ٢٢٢] ﴿نِسَاۤؤُكُمۡ حَرۡثࣱ لَّكُمۡ فَأۡتُوا۟ حَرۡثَكُمۡ أَنَّىٰ شِئۡتُمۡۖ وَقَدِّمُوا۟ لِأَنفُسِكُمۡۚ وَٱتَّقُوا۟ ٱللَّهَ وَٱعۡلَمُوۤا۟ أَنَّكُم مُّلَـٰقُوهُۗ وَبَشِّرِ ٱلۡمُؤۡمِنِینَ﴾ [البقرة ٢٢٣] These two ayaat are important. The first one seems to imply that we should only approach them where Allah has commanded us. The next one however, makes it seem like we can do whatever we want. Could this be one of the examples of naasikh mansukh?