Old Bamboo

The "Old Bamboo" endearingly refers to a long bamboo stick famously coined by Dick Van Dyke in his breakout role in Chitty Chitty Bang Bang through the song "Me ol' bamboo". More colloquially, the old bamboo can refer to a penis experiencing erectile dysfunction, possibly due to age related illness.

"Sorry love, me old bamboo don't work the way it used to"
"The pandas gone an' chewed on me old bamboo, the greedy bugger"