My partner has given me the choice on weather they should transition. And I'm not sure what to say/do

my partner afab (assigned female at birth) has asked me whether they should transition, and I'm not sure how to react as they've given me the decision themselves. I'm bisexual but for a while, I've been wondering if it's to do with trauma I had growing up or not. as a result, I've never had any noticeable attraction to male's but in terms of females, I've had many more partners in the past. and recently they've pinned the entire descisions on weather or not they should transition and I'm not clear on what I want as I want them to make that descision but they've also said they love me so much if I said don't they'd not get it they have also said in past conversations that they want it to be my decision and that they'd do what I say. but in other conversations we had, they've stated they'd attempt if they didn't. I've tried convincing them to make that call, but their adamant that it's mine