The same question came up in the last thread. The best we could find is either Vorarephilia (arousal from eating or being eaten by a sexual partner and being completely 'inside them') or Unbirth (basically being returned to the womb). There doesn't seem to be a specific "Pregnant Men" fetish that we could find, and I don't think we wanted to dig into that rabbit hole much deeper (/shudder, that's probably furry slang for something)
Also, Vorarephilia merits a wikipedia article if you want to read more. Unbirth will get you on some kind of furry fetish wiki. Tread carefully. Never has this gif been more appropriate;
If this thread didn't fall under GAF's rules about NSFW content, the level of horror unleashed upon your eyes would... well, yeah, you see the gif.
There's a lot of fucked up people out there. Before, you could count on them staying in their dark basements and keeping their creepy fetishes to themselves. Thanks to the internet, they can meet up with each other anonymously, leading to a proliferation of both fucked up materials and the impression that such fetishes are 'normal'. And then you bump into people at the mall wearing tails and barking at each other.