"And just for the record, I don't think condoms should be free either... close ur legs and hold ur bladder, end of discussion [sic]."
Williams' tweets prompted hundreds of comments from other users who were quick to point out the problem with his argument.
One user wrote: "Imagine being this stupid to think that women can force their uterus to shed off all the blood."
Another, @CraftyRenate, wrote: "Rude AND ignorant. Your parents must be so proud. So I guess you think women PEE out babies then too. LMAO [sic].
Ruth, using the handle @hvckleberries, added: "It's not feminism, it's literally just biology. Girls don't control their periods and blood doesn't come from their bladder."
Youtuber and musician Emma Blackery said: "Want to sarcastically tweet #ImWithRyan #HoldYourPee but I fear people will genuinely think I'm this level of f***wit".
On his profile, Williams claims he is a "politician and youth adults spokesperson", as well as a self-styled "meninist" - a movement that takes a stand against feminism.
He appeared on the televised Brexit debate and has been interviewed by national newspapers over the matter.
Some of his comments have been shared more than 800 times since he posted last night.
Following the backlash, he added: "Yo I'm so lucky my girlfriend isnt crazy like these feminists and she never bleeds lol always clean.
"Wow I gotta go, my girl waiting for me and I'm here reading all these single bloody b****** tweets to me. Need to get my priorities right."
He is still getting comments from annoyed users on Twitter but is yet to back down and seems to stand by his tweets.
