All Witches Are Vixens, or We Did (Not) Summon a Demon

And how did I manage to summon the greater demon?! What? This impudent fellow is ready to take part in my experiments and even provide his tail for it?! Well then—we witches are very curious creatures. But let him not hope for anything! I need the tail only for scientific purposes! Hey-hey, demon! You’re the one who offered it to me! And that still isn’t a reason to marry you! 
This is the 3rd book in the cycle “All Witches Are Bitches.”
All books in the cycle can be read separately.