Obsessed With My Boyfriend Cumming Inside Me & Carrying His Child

I've never been in a relationship as serious as this one and I realized very early on that this is likely the guy I want to spend the rest of my life with. Ever since coming to that conclusion, I have not been able to get enough of him. I need him as close as possible and it never feels close enough. I need him inside me always and that has developed into a fascination with letting him cum inside me. I'm always very careful about my timing with regards to when I let him do it so as to avoid any unwanted consequences, but I really just want to let him do it all the time. I want some part of him inside me all the time. I really wish I could see it and feel it more too. I love when he fucks me hard at an upward angle and I can see his hard cock poking up near my stomach from inside. I want to watch his cum fill me, I want to feel it inside me, and I want that feeling to last for more than just the moment he does it. I have no desire to have kids (at least not at the moment), but the thought of carrying around a piece of him like that just drives me crazy. I think I would cum so hard if he started talking about breeding me during sex. I fantasize sometimes about being a couple weeks pregnant and not showing yet and it being a secret between us, him teasing me about what I can or can't do with a baby inside me and talking about how everyone will know how much I love him as the weeks go by and I start showing. I would love to roleplay this with him. I imagine him fucking me while I'm tied up and him telling me he's gonna put a baby in me and cumming in me multiple times and I imagine continuing to play in that space throughout the week. Going out somewhere and having him put his hand on my belly and ask about the baby in a whisper, getting food and him making comments about me "eating for two," asking me how it feels carrying his child and how it feels to know it'll keep growing and get harder and harder to hide. I feel like I could cum just thinking about it. I think the sex after that would be so crazy. I think I'm just worried that talking about this extent of my fantasies might change his perspective of me and that he won't be able to separate the kink from who I am outside of it... like I don't want this coming up outside of a sexual context really lol. I don't think I'll have to wait long to tell him though, he keeps telling me how much he loves cumming in me over and over and filling me up with it and we've also started to talk about how we feel about having kids (we both are uncertain but agree that hormones make us think crazy thoughts from time to time) and I suspect that he may even have fantasized about getting me pregnant earlier on in the relationship.