F or six weeks now, we have been a two-cat household. Five-month-old Lemon, Peaches’ three-legged kitten, adorable in all of the ways you might imagine (and some that might not even have occurred to you yet), joined Maynard, our six-year-old adult female (we thought she was a boy when we named her, alright?) to make a new life of cheerful cohabitation in our split-level home. From the start, though, it hasn’t been that. Cohabitation, certainly—a reluctant, wary sort of working truce seems to be in play most of the time—but there’s been nothing cheerful about it. Lemon’s behavior was, in a word, shocking. Entitled in a way only those among us who are both shiny and well-loved can be, she could be seen repeatedly…