Riley Gaines is going to be a mom ... announcing she's pregnant with her first child -- and taking a dig at Simone Biles in the process.
The former collegiate swimmer turned right-wing commentator revealed her big news at a Turning Point USA event on Saturday ... bringing up Biles' recent comment comparing her height to a man's in order to do it.
Riley says she thought it was totally ironic when Biles said, "bully someone your own size, which would ironically be a male" .