[SunshineMpreg]

You can actually have Male sims in the Sims 4 get pregnant in the Base Game.
All you have to do is change their gender setting to allow for pregnancy in CAS.
(You can keep the ability to pee standing up as well as allow for pregnancy.)

Anyway here are some slightly edited screenshots from my Sims game.
(I used the pose player mod to get the cool poses and some general custom content.)

This is Jake Mastors and below are some of his pregnancy shots!!





The parts I edited were the lower stomachs (as the shorts curved up it unrealistically)
and the crotch because sims dont have anything down there.