Natural male with 1 testicle since high school. Can I add an artificial one? (Photo)

I am a 49yrs old. Natural real male. I only have 1 testicle after a surgery in high school. I had a vasectomy at 25yrs old. When nude and erect I look like a Unix with no testicles. My wife and I are swingers and I have a “larger penis” which at swapping clubs draws a lot of attention but with only 1 testicle which hides due to no sack when growing its a-self esteem issue and profoundly uncomfortable to perform. How much to add a artificial one plz