Yanking the Tulip

My Dad and I were recently discussing a mutual relative. This relative is having “Issues.” I asked my Dad what kind of “issues” this relative was having and my Dad said, “He’s been yanking his tulip.”
We started giggling at the terminology.
My family is Mormon and apparently masturbation is against the rules. My Dad, as irreverent and funny as ever, commenced to tell me how he worked at his father’s lumberyard as a young boy with all his relatives. He kept asking his cousins what the word masturbation meant. They wouldn’t tell him, so he started to guess.
“Does it have something to do with music?” he asked.
They thought for a minute. “Yeah, it could.”
“Is it a solo?” My Dad asked.
“Well, it could be,” they replied, “but it’s a lot more fun when it’s a duet.”