I have gained weight in the belly over the years. It seems my penis is getting smaller each year. Is it do to the weight gain around the middle?
Possible, more likely at 61, your eyesight isn't what it was at 21!! Belly can also obstruct/alter views as can poor lighting! If it is still working at 61, count your blessings instead of your inches!!
Your penis isn't getting smaller. It's just that the fat and skin surrounding it have gotten larger and looser, making it appear that your penis is smaller. You're normal.
Yeah, you probably just can't see it as well because of the weight gain. Size perception can sometimes be a decieving thing. If I look striaght down at my flaccid penis it sometimes looks quite small, but if I turn to the side I see how decieving some views can be. It looks quite thick from the side..
I've got you beat by a few years, I have put on some weight recently and the protruding gut makes my penis look smaller until I turn to the side, as was mentioned.
Re: Penis size at age 61 
Belly can also obstruct/alter views as can poor lighting! If it is still working at 61, count your blessings instead of your inches!! 
