When one partner likes to be naked

I re-married 8 years ago, my husband and I are both in our late 70s. Turns out he likes to garden naked. (we moved a few years ago and to a house where we’re not overlooked). He gets irritable when I say I don’t like him sitting on the furniture or wandering around gardening. Bending down to plant or prune. (If you see where I’m going with this) He just says “well don’t look!” He’s fit and active and not mentally impaired, Just rather stubborn. Am I being unreasonable?