Let’s be adults here: everybody masturbates. It’s a perfectly healthy thing to do - though it’s still somewhat risqué to bring it up so candidly in conversation. Thankfully, just about every language has its own code phrases for the deed - some of which get pretty surreal.
When it comes to masturbation, there are some trends that transcend language. Male masturbation in particular is often a strangely violent affair. The English say they’re "choking the bishop", while Germans say they are "Jürgen würgen" (choking a guy named Jürgen). A lot of Polish expressions for beating one off seem to actually involve beating something - whether it’s "walić konia" (hitting a horse), "walić szkopa po kasku" (hitting a German on the helmet - possibly because of German uniforms in the Second World War) or most strangely, "trzepać kapucyna" (beating a monk). On the other hand, a "kapucynka" (a Capuchin) is also a type of monkey, so it may be linked to the classic English phrase "spanking the monkey."
The French, unsurprisingly, think of food - there you can "toucher la nouille" (touch your noodle), or "chatouiller le poireau" (tickle the leek). The Italians, meanwhile, use a lot of tools: "farsi una sega" means "to use a saw", which sounds pretty painful if we’re honest, while "ludicere il manico" means to "polish the handle." And in Spain they seem to be fans of the old "sit on your hand and pretend it’s someone else" trick - there they pretend to get a visit from "Manuela."
Sadly, the stigmas around female masturbation are still much stronger. But there are some options out there - the Swedes, for instance, have coined the delightful term "klittra", a mix of the words "clitoris" and "glitter." In Italy they call it "ditalino", which sounds almost onomatopoeic - you do use your fingers, after all. English women can refer to it as "flicking the bean", while Germans say "sich die Perle putzen" (literally "polishing the pearl").
Now all that remains is to lie back and think of England. Or Poland. Or even Manuela.