Judging by your photo, your "junk" looks similar to many of the men that I've seen on the nude beach of Ptown this summer - most of them in their 50s and 60s. I say that just for comparison of what I have found as "normal" for a similar group of people.
The arm-chair psychologist in me suspects that your self-declared "esteem issues" around a loss of girth and length are legitimate, but may be somewhat beside the point for your relationship. You have a husband who presumably knew about your medical history and still chose to be with you. Do you think that your husband would still ask to introduce a 3rd person into the relationship even if your cock were a "spunk" firehose? If so, why does your husband
really want to introduce a 3rd person?
I'm not judging:
- Is it for sexual variety?
- Does he just want to play out a fantasy?
- Is this 3rd person a guy that he wants to be intimate with and doesn't want to "go behind your back"?