Given the information you have provided, I would first need to ask you what is missing or what part of your sex life isn’t being met pleasurably at this point? I believe in adding to whatever you are currently doing in order to
spice things up and reignite that intimacy. If size is truly the issue, have the two of you considered using a penis extender for mutual pleasure? Have the two of you considered using dildos and/or vibrators for her internal pleasure? There are also adjustable sleeves that she could manually stimulate you with if you two would like to participate in
mutual masturbation.
How is your non-penetration sex? Do the two of you provide oral sex for each other?
As for her being uncomfortable with certain things you want to do, I don’t have a lot of information to go on. What I can say is that in many relationships someone is not always going to be on board with everything their partner wants or suggests. Have you two discussed what exactly it is you are seeking to incorporate into your sexual repertoire? Has she expressed what it is she is uncomfortable with and why it makes her feel that way? Are there alternative ways this need can be met that you are both comfortable with?
Perhaps there is a way to start out small with whatever this act is and build up to the level you desire. Express to her how important it is to you while validating that you truly don’t want to make her unhappy or alienate her from pursuing deeper intimacy. Also, ask what else she might be willing to try or if she has any ideas that would be a variation of what it is you want to do. Including her is a great starting point. You could also suggest trying it just once from start to finish. If she agrees, have a safe word or some agreement that she can stop if she genuinely makes the effort and can’t get behind it.
Make sure to iterate how much you would really appreciate sharing this experience with your wife. If she still refuses, find out if there is a way that you can still respectfully have this aspect incorporated into your life. If not in person, is there a way via the Internet or
porn that you can still have this experience play out in some fashion?
Remember, though, that you expressed this is about mutual shared pleasure. You both have to be giving and receiving. This should not be done at the expense of each other's comfort.
