Is it possible for trans men? I know it's possible for trans women, so now I'm curious. Eventually, I wouldn't mind having my share of one-night stands without having to go through the whole explaining-I'm-trans process.

I've never done it, so I don't know. 

I would imagine that it's dependent on what kind of sex you're having - penetrative or just fondling, etc.

It may be possible to have rather guarded sex using a highly-realistic cock like the RM without someone being able to tell that it isn't a biological member, but I don't know for sure.  If you're just having oral sex or masturbating the other participant, then again - it may be possible to not disclose.

i'm hoping that phallos will start consistently being amazing, because i feel like that would be the only way for that to be possible. even then, i don't know. it still wouldn't be possible to, uhh, ejaculate, like a cis man. i don't know. that's what i'm hoping for someday as well.

I believe so. Specifically what I think would give it away is the no ejaculation however on some post op sites I've talked to a guy who had a meta then phalloplasty who can ejaculate. What he said's that if something called the skenes gland is kept intact it's possible with orgasm. After going through all those steps I believe stealth sex is definitely possible.