Any help appreciated again

I am once again asking ;-; but I remembered a few more things and perhaps someone will find the manga this time lol so basically the seme wants to eat the uke's ass but the uke doesn't want him to lick there because it's dirty and he is scared of accidentaly farting on the seme's face, the uke hesitantly agrees and washes his ass inside out in the shower then goes to the bed where the seme is waiting, the uke sits over the seme's face in a normal sitting position while the seme holds his hips (the uke is not on his hands and knees) the uke is super embarrassed and this next part I'm not really sure but once the seme puts his tongue in and all that happens the uke gets super suprised by the feeling he accidentally sits on the seme's face basically suffocating him there for a bit and perhaps injuring him. This also could be a doujinshi of some anime ship but literally my memory is the worst I really don't know