There isn’t a way to toggle consent on or off - the character is just super horny and she always consents. You can jump to avoid them, but that said, if you’re at the very start of the game, you might find them grabbing you to be more of a neutral action or convenience soon.
Spoilers! Don't click if you prefer not to be spoiled.
Once you’ve used the dildo you can “ride” the purple tentacles around the map, and as the guide lady says, this means you can travel on the swamp waterfalls and get to new areas.
In any case, thanks for the feedback!