Would outing a trans person in this situation be justifiable? Sounds wrong, just hear me out, please

Would outing a trans person in this situation be justifiable? Sounds wrong, just hear me out, please.
Yes, it’s an attention grabber, but I’m in a really uncomfortable situation and I need help (especailly from trans people). Also sorry if I mix up the pronouns of this person, kinda confusing in this context and I couldn’t find them listed.

Attached: plshelpimadethisjustforyou.png (1501x998, 3.61M)

I broke up with my gf a few years ago because I moved to another country and
we couldn't see eachother anymore (We were underage, her parents are very strict, and didn’t know we were together. Neither had money to fly.). We were long-distance for 6-7 years before the pain was too much to bear for both of us.
We broke up on good terms and she's still my best friend.
Now, a few week ago, a person (whom I suspect is trans because they're taking estrogen and a few other posts I found) showed interest in her. They go to the same university and he asked her for help with some projects as she is a few years older. She showed me a picture of him, she thought I might find him cute and attractive, which I did (I'm a bi/pan guy).
Couple of hours ago, I was browsing NSFW subreddits like I sometimes do (strictly research ofc), and I ended up stumbling upon a picture of what I'm now 95% sure is him/them. Naturally I went to the profile to check it out. Age matches, hairstyles match, nose, eyes, chin, neck, adam’s apple, eyebrows, I even looked at the hands and the way they hold the phone. All the dates roughly coinide with stuff like hair changes, but not consistently (uploading older photos?). If that wasn't enough, I found older photos on their insta together with newer pics, and there is a clear difference in the face. They obviously look more feminine now, but if my math and knowledge are correct, they’re only a year or so on hrt.
PART 1

My ex and I always told and still tell eachother everything about someone we find attractive and about everyone that makes advances on us. Neither of us have had any relationships/partners since we broke up. We still have strong feelings for eachother, but since we are currently unable to be together, we agreed it’s ok to see other people as long as we talk about it and everyone feels comfortable. There were already people interested in both of us, and we discussed this fully. One girl that was into me sent me her Tumblr with nudes, I told my ex and she wanted to see (I mean, it IS publically available for everyone to see, right? I don’t think it’s wrong in that case, it would be a completely different thing if that girl sent me a nude, personally, for my eyes only. Then I wouldn’t show my ex, no matter how much she asked for it, but I would tell her about it. The two of them even spoke together and the girl knew the situation. Nothing came of it tho.)
PART 2

Thing is, I don’t fully know if she is ok being with a non cis male person. We never discussed that. She also doesn’t know much about the trans community, and only recently did I explain some things to her after I sent her a music video of a trans artist I adore. Unfortuneately I couldn’t figure out her opinion on the matter, and she didn’t comment when I said I find that artist quite attractive.I also tease her that she’s bi because of memes (likes frogs, cuffed jeans, thumbs up on every photo, that stuff) and because lesbians/bi girls hit on her often (she’s a tomboy, petite, short hair, boy clothes). However, she’s constantly saying she’s straight, adamantly, but she’s into effeminite men (I myself am quite effeminite, but identify as cis and would never go on hrt. More of a twink than a femboy I guess, long hair, never shave body, wear suits etc.). She obviously doesn't know that he is possibly a she/they, and I found posts from them saying they’re not out yet (To anyone? To the public? Not sure).
Another “problem” is that she has a very strict no online nudity of any kind policy (At least for her, I said I’m not interested in posting myself, but she didn’t say how she’d feel if I did). Hell, even when she sent me nudes, it had to be through encrypted messeges and I had to promise to keep them in a hidden encrypted folder. But this person...it’s all shown, multiple times, from many angles. Butt, penis, cum, dildos, you name it. All solo though. They even have an onlyfans.
Again, they are all public, their face is shown on all profiles I found, even parts of usernames are a nickname of their real name. It is completely possible for my ex to stumble upon them by herself. If they weren’t trans, I wouldn’t hesitate to just ask her if she wants to see his NSFW accounts. It’s public, you don’t post pics of your face if you’re concerned someome might find you. But I also don’t want to out them.
PART 3

I really don’t know what to do. I feel an obligation to be transparent with her, but I don’t want to hurt someone that isn’t out yet.
Since she knows his insta, should I hint at it like: “Hey, I found this older pic of him, doesn’t he look more feminine now? I think he may be on hrt.”
Should I just keep this to myself and try to forget it, and know I broke my promise of talking about everything?
Should I first wait a little to see how the situation between them develops?
Should I send her all the links but tell her to keep it secret from him? If they eventually come out to her, she just says “I had my doubts from older pics.” “I saw the outline of your boobies by accident.” and stuff like that? That she found the profile herself but waited for them to be comfortable to come out?
Should I just show her one pic of him/them which is SFW to satisfly my morbid curiosity if that is indeed the same person?
Should I ignore it all and just say he’s ok and that I wouldn’t mind him being her bf and I support them? (To be honest, I wouldn’t mind him being MY bf….or dare I say, “our” bf. Tho that is just my bisexual sandwitch fantasy...lest...she said she’s ok with poly if everyone is into eachother...once we finish our degrees and can move in…one can only dream, eh?)
I know not all trans people think the same and no one here can speak for how this person would feel, but I’m truly lost and seek guidance. How would you feel in this situation? I feel like I will betray someone in either situation. Either I’m outing someone, or breaking a promise.
FINAL PART

it's always wrong to out someone like that yeah

yeah I don't think it's cool to out them

user, are you sure you're not trying to undermine this guy's chances with her by outing him? It takes a long time to get over a relationship as lengthy as yours. It'd be understandable if you were doing that unconsciously.

But yes to answer your question that'd be very fucked up. This is their information to share. Being closeted is clearly important to their life right now, for reasons you may not even be aware of. It would seriously disrupt their life by outing them. It'd make them feel violated and hurt. Being outed is a horrible feeling, especially if you're in your early transition and still figuring things out.

Also while their nudes are technically out there for anyone to see, they were posted under an anonymous pretext. Clearly they do not want it to be linked to their real identity. It can't be helped that you found them, but sharing them is contrary to what this person wants and would probably hurt the friendship with you ex (especially since you're assuming she doesn't approve of this behavior).

Just let sleeping dogs lie. Please. Nobody gets hurt by you not telling your ex this. Outing him could potentially fuck up things in his life (especially if it got out to other people). I think your ex would understand if you didn't tell her something as to not put someone at risk.

Yeah, you're right. It was just so unexpected. The sheer coincidance of me finding the profile within the first few weeks he showed interest. Guess I'll try to not think about it, but I'm sure that if they do progress with sth, she'll tell me.
>user, are you sure you're not trying to undermine this guy's chances with her by outing him? It'd be understandable if you were doing that unconsciously.
Consciously I'm sure, but I'm not conscious of my unconsciousness. But I must admit that at first it was difficult, it has been 2 years since we broke up. I don't know, I feel ok with this guy. Maybe because I also like him, who knows. I must say, posting your face, even if you believe you're anonymous, is dangerous business.

You're doing the right thing user, good on you.
>I must say, posting your face, even if you believe you're anonymous, is dangerous business.
Yeah that is an incredibly unwise decision. Not saying what they did was good or smart, but the nice thing to do in this situation is ignore it.