Hi. I've been married with my wife for 12 years and we have two children. She's quite vanilla, no particular kinks.

After the birth of our second child one year and half ago we fucked just once, a quick one more or less one year ago. She told me she wants to have inserted a IUD to avoid new pregnancy but she's keeping moving forward this.
I wank a lot and i don't really miss her pussy, I don't like condoms.

i'd like to "make it official" but i don't know how to talk with her... "honey i don't want to fuck you anymore"?
As i told you she's vanilla and i think she won't understand this kink, and she isn't dominant in any way.

any advice?