Don’t ask the internet.
But as you have. Do not do it just to please him. That will lead to issues. If you do it. Be sure it is something you are choosing for you as much as him.
If you are in any way uncomfortable. Then future issues can be amplified by the resentment.
Only you can know if this is something that appeals to you.
And only the two of you can evaluate how likely it is to lead to jealousy or resentment.
If you cannot openly talk about that risk and how you or your partner may respond to negative feelings. Neither of you is really ready for this,
Your never being with anyone else is something you should discuss first. Your comments make it seem like that is important to you. Start by talking with him about how that makes you feel. Compared to his experience. If he cannot understand you opinions and emotions. Positive and negative on that. You need to enhance you communications/mutual understanding first,
Being able to share both positive and negative feelings. Without blaming each other. Is essential for a marriage to survive anything like this.
Likely old enough to be your grandfather. So while it not an activity I have any interest in myself.
I have dated a woman who faced this choice in the past. We are still friends, so she shared her advice. With a little of my own.