My partner is a closeted transgender person. They came out to me pretty soon in the relationship (4 months in) then later when I expressed openly that wasn't for me they declined it ever being a thing, and denied ever browsing content related to it. It's odd because they still get upset when I bring it up as a concern so I stopped altogether.

Yesterday, they brought up me not being intimate with them in any way. This was after they told me explicitly they refused to take an STD/STI test and claiming I was the only they ever slept with. I have some doubts on this, but I have no proof and my partner's been having a few people over at odd hours and also talked about having a roommate with some guy. I didn't say it outright but to protect myself I refuse to have sex with them ever again until they have a test. Thankfully it's an LDR so I don't have to do much to push them off me. 

Not really sure how to not yell at them "I don't want to sleep with you because you're in the closet and already admitted to transfeelings and you've possibly been sleeping with other people!" but I sure wish I could without being referred to as crazy or abusive. It got so bad I don't engage or fight with them at all anymore, but they'll so sad that I don't do that anymore too. But I'm exhausted. It's easier just to let things collect dust.