It's like the scorpion asking the frog for a ride across the river.
The frog is suspicious, but the scorpion smooth talks the frog, assuring the frog-why would I sting and kill you, we would both drown-that's so silly!
The frog takes the scorpion and lo and behold-he stings the frog.
And as they are both drowning, the frog says-but why-why did you do this, now we are both going to drown.
The scorpion says I know, I know-but I can't fight my nature!