I totally agree with all the other responses - I have a daughter who is almost 7, and I can't imagine not having our nightly snuggles and reading time. For us it is a very special time of the day. The house is quiet and there is nothing to worry about getting done. It's just the two of us (although sometimes we invite daddy to join us) and she tells me what's on her mind and we take turns reading. I take over reading when she starts to get sleepy and eventually she drifts off. The sweetness of her snuggliing up to me to fall asleep is something that neither of us want to give up. I'm sure that one day (hopefully a long time from now), she'll want her own space. But for now, and as long as it lasts, it's nightly snuggles for us!!
So my advice - explain to your husband what the time you spend with your son means to the both of you, and hopefully he'll understand and be okay with it. Maybe he should join you and your son for a book and then he'll understand why it's so important to you. If not, I hope that you'll continue to take the time with your son anyways because you both deserve the comfort that you get from your routine.
Good luck! Enjoy it while it lasts.