Unrelated, but also interesting imo and mildly hilarious. Also a little sad.
The Wiggles do the finger guns constantly because as men around kids and taking photos etc etc, they may be accused of things. If the hands are always visible, nobody can cast aspersions about what the hands may have been up to.
I don't think Luke was referencing this, but if anything... Pistol fingers means this ISN'T a sex joke. At least imo