Why couldn't he just listen to you for once? It was so tiring, arguing with this stupid cyborg, he was so ignorant, you were convinced he was draining the life out of you.
Here you were, fixing Boothills mechanical body once again, he truly sees that body of his as invincible, but it's not. You've tried telling him so many times to 'be careful' but he never listens.
Boothill had gotten used to not feeling much physical pain due to the fact it was mainly his robotic body that was attacked during fights and you really wanted to get your point across that you didn't want him throwing himself around like this. That's when you slapped him across the face.
He looked SO shocked at that, the feeling of physical pain he had not felt for years shot straight through him, he was definitely starting to realise that he was in fact not invincible just because he's a cyborg. "I-I-I see what ya mean darlin'..." he reluctantly admits while you go back to tightening the loose screws on his body.