It's a start.

Clever idea to show what happens in the first frame, but here's an idea
Right after the first frame, add a fast fade out to black and a fade in to the actual animation
Nearing the end, make a slow fade out to black and a fast fade in to the first frame.

I LOVE these animations... but I wish they'd leave out the single frame they use for the thumbnail, or at least leave it in for a few EXTRA frames, that way we don't get the weird distracting flash of that single "off" frame.

How is this explicit?!!!! Fuck I hate "Tag what you see"!!!! It makes us miss out on so much of what we look for here!!! Like all the "Irrumatio" pics and vids that are labeled only "Fellatio". Learn your shit!!!