Husband having expectations on me when I still haven't bonded with my step son

My step son has been living with us for 10 Months because he's been witnessing DV between his mom and her boyfriend and they have basically left out of state. He's been seeing this since he was 9. He's 15 now. He doesn't really want to bond with me or my 6 year old daughter. He kind of just does his own thing and I've tried. My husband lost his job and just started a new one as a truck driver . He's going to be gone this weekend and he was telling me I kind of need to take over a few things with my step son. Some things I can understand like driving him to therapy Friday. Some I can't because he isn't really interested in bonding with me. As I mentioned back in August he sometimes has accidents at night. Most likely trauma related. It was sometimes. Now it's more often so my husband just bought him things to wear to protect the mattress at night. My husband just told me while he's gone, remind my step son to go pee before bed to put on his stuff. I'm not comfortable with that. Like I said I've tried to bond with him and in my first post I offered to wash his things but he did not want me to. We aren't close. He doesn't want to bond with me. I don't think my husband understands that. I tried telling my husband and he just said if I don't remind him he will forget and just be more embarrassed and uncomfortable. Ughhh does anyone have any advice. Also maybe some suggestions on how to bond over the weekend?

Edit: @To the person with flowers... Do you not know what a deadbeat mom is? I literally asked how to bond over the weekend. Back in August I was trying to be helpful and he didn't want it. All I've tried to do is bond and he keeps pushing me away. How am I a deadbeat)