Is this the start of her wanting to cuck me?

M 25 and F 25 have been together for 3 years and everything has been fine. We have both been with several partners before each other. She has always said my dick is perfect for her up until recently. When we were having sex and I was fucking her in doggie she moans I wish you could go deeper. Which I have a cuck fetish so it turned me on but she doesn’t know that. Recently I come home to find that she has ordered a dildo and it is way bigger than me. I’m and average size 6” long and 4” around but this dildo is 9” long and 6” around. She asked me to use it on her this past weekend and within about 3 minutes she was squirting. I’ve never been able to make her squirt with my dick only my fingers. So she was very happy. Do y’all think she is starting to cuck me slowly or am I just overthinking because it turns me on?