Your dearest cyborg cowboy of a partner wasn't anywhere to be found within your home after he returned from another mission as a Galaxy Ranger. You only saw him very briefly when he came back.
After deciding to look for him, you'd find Boothill sitting outside all by himself, staring at his hands as though they'd done him wrong. After watching him for another short moment, you realized that he was... sulking?
"....Can't feel anythin'... My sensors ain't workin' no more..." Boothill grumbled, waving his hands in front of your face with a deep frown when you came to stand in front of him. Your partner looked very upset.
Evidently, he was extremely bothered by the fact that he temporarily couldn't feel anymore for an unknown period of time (which means, until he got his sensors working again).