I don’t think I’ve ever used or even heard the phrase… unfortunately…?

But “the pussy of a dick” would be something like “vitun kyrpä”, which is something I may have used once or twice or thrice or…

But it’s more like saying “you fucking dick”. “Vittu” is our “fuck” more or less, contextually, although if you take it literally it means a certain type of female reproductive organ, yeah. But then again if you take “fuck” literally it’s having sex.