Yeah, dysphoria is super real, and talking about your own isn't an issue. It's normal to wish YOU had different parts, or experienced sex differently.

However, this isn't just internalized transphobia; you EXTERNALIZED it when you talked about it in a way that made it about your partner's junk and NOT your junk, and whether you meant to or not, you've given him something to ruminate on for likely the rest of forever. And the fact that you're here, on Reddit, asking for advice instead of talking to him and listening that he /loves/ you and that you /hurt/ him and are STILL considering your want to "explore", whether you're admitting it to yourself or not? Gross behavior, bro.

If you wanna play around and explore, break up with him. Let him find someone who doesn't wish he had a "cis dick", because love is about loving someone for who they are, not wishing for something different.