To be fair, I think they were originally produced for film / TV, not for psychos who were pretending to be pregnant.
To be authentic, they need to weigh about 2 stone and have a Bit which presses into your bladder so you pee every 5 minutes.
Now I’m thinking; does it have poppers?
Can you imagine going to a public loo and the Whole belly dropping down with a “thwump” in the stall next door...?!
Has she popped over on a private jet to give him a quick blow job?