Well, true story time
I bought a toy. This toy is a 'realistic' penis and balls with mechanical thrusting and vibration. It is soft silicone, around 8 inches long and a good 1.5 inches in girth, bit more at the head.
The start button is on the bottom of the balls, just in front of the suction cup and it has a remote but, oddly, you cannot turn it on with the remote -- just the aforementioned spot under the balls.
I was going to pleasure myself with this but one small, teeny, tiny, definitely not being ironic here, caveat: I have never fit anything this big in me.
In my research, at least until I can stretch myself to accommodate this big daddy, everything said, "use lube". A lot of lube. More than you'd think you need and more than you'd prefer. And, preferably, to save the material of the device, water based.
Okay... I have it ready to go, fully charged, and am all, "let's get this up in my guts!"
I suction it to the rim of the tub, straddle it, line it up and sit...and promptly lose my grip. With more than a bit of spring, from the suction angle and me trying to line it, it has considerable tension and I lose my grip, causing it to spring back and, in its arc, it makes a very solid connection with my testicles.
So, after the world returned to not being a fantastic display of fireworks...Try number two!