Same here but i jacked with my dad since i was a kid. No gay sex between us just masturbation sections together for years. We start one day taking a shower together and just happened. He get hard at the shower and i told him i dont care about it. I was 16 and just do the same and jack off together until we cum. Since that day we never stop.
Many men of his age are not able to feel the pleasure anymore so its lovely seeing him making the most of the days he has left to enjoy lovely orgasms from his very old cock. And he has a very nice looking penis too.