Hear me out. Boothill is absolutely obsessed with physical touch and WILL always have an arm around your waist. He will shamelessly kiss you in front of others if anyone dares to flirt with you in his presence (he promised not to shoot anyone anymore). He WILL slap your ass if you walk past him and smirk with his arms crossed when you look back at him. Why? He knows you can't really slap his ass back (this one might hurt), but you're very welcome to try, he won't stop you. Will pull your chin up with his fingers and kiss you whenever he wants. Boothill will bite you on purpose with his sharp teeth to mark you, only to kiss the purple spots better, so you can melt under his touch. Boothill thinks the sidewalk rule is very important - that's why he pushes other people on the road, so you can have more space to walk, while holding your hand. He pulls you towards him so you hit his firm, metal chest with yours while he laughs, cupping your face roughly and gently kissing your cheek. He wants you to pull on his hair when you kiss, so you can get goosebumps when he groans into your mouth and feel his cold fingers caress your soft skin further down.

PSST! boothill relationship headcanons and more thirst here!