Hi, I'd like to help you with your question.
It depends on whether or not you want to be tied up. What is normal between a married couple is whatever they are comfortable with as long as it is not forced on the other partner. In other words, both partners have to agree to it and it does not involve anything illegal.
If you are not comfortable with what your husband is doing, then you are not obligated to do it. If you find that your husband cannot sleep with you if he does not tie you up, then he may have issues that need addressed by a therapist.
You might try suggesting other ways to pleasure each other that you enjoy. If he is willing, there are a lot of options out there.
Please let me know if you have any more questions.
I hope this has helped you,Kate