The narcissist feels the same way about the new supply as they did with you in the beginning during the love bombing period. It's all a facade. The mask just hasn't slipped yet. Focus on your healing and not on the narcissist. The more you force yourself to not think about them by redirecting your thoughts, the better off you'll be. Practice makes perfect. Perfect your craft of not caring about what they're doing or who they're doing it with. It's all fake, just like it was with the you. Stay encouraged and be strong. You got this!