DEAR ABBY: I am in a loving relationship with a kind and caring man, “Byron.” He has a preteen son, “Eli,” from a previous relationship. Eli stays with us several days a week, and I watch him while Byron goes to work. Byron and I would like to spend the rest of our lives together, but I’m uncertain if I can truly be a stepmother to his son. Eli often yells at and hits his dad. He calls his dad stupid, among other things. He asks for expensive items during every visit, often refuses to bathe and won’t eat anything other ...