diddly fiddler

(noun), a term used as an alternative word for sex, or someone who has a lot of sex

"wow! Kaden probably fiddles so many diddlies!"
"Dude, your such a diddly fiddler!"

bum-fiddler

Derogatory. One who handles their anus for recreation. Similar in use to wanker.

"That bum-fiddler just cut me up."