I recommend this to any couple.
It caused my wife's reaction to be more than any other toy we have tried so far. She likes to insert it herself. When my hand is shaking back and forth, apply pressure to the top and apply pressure to the bottom. It is not uncommon, but it applies to toys.
The only drawback so far is the heavy chemical odor. I washed it twice with hot water and safe soap, and the chemical smell has not dissipated.