I've noticed the same thing while straining. I've even run throught house to show the wife. After three years it's good to see the "old boy" every once in awhile. As for the sperm, I think mine went on vacation when the hormone treatments started and never came back. I think they are in Disney World or The Magic Kingdom. You started all this, so I could not resist.
I do believe that production is based on need and that the body does absorb them. I can't get the picture out of my head about dragging the "guys" around in a wheelbarrel or garden cart going to the store or out for dinner. I can see me and the wife going out for dinner and asking for a table for 4.
Don't worry. Both items are normal. The straining increases blood flow, thus energizing the penis, some times. The sperm production will not be a problem.
Thanks for adding some laughter to my day. Love ya man.