Boothill had a partner once (how else would clementine exist?), the two were happy and yet the other never got to find out he was to be a father as he sadly passed. (Was either shot or ill). Boothill now carrys with him his ashes and what he had left of him, their daughter. Until both were destroyed in the destruction in his planet, killing everyone he loved.
Also what kind a pet would he and Clementine have :) -Dog anon <3