Well at least the ex told ya

It's as much your responsibility to get tested regularly and make the guy wear protection as it is his. In most men Chlamydia is asymptomatic. It's easy for a guy to not know he has it without regular testing. You should be tested prior to engaging with any new partner. It shouldn't take your ex telling you. to find out.

His family doesn’t have to know. It’s not like you slept with his brother or his dad right? Right? Uh oh!

I doubt he'll tell his entire family about it. This is something that should stay between the two of you

They'll probably think your name is Chlamydia.

Umm hello have ya not seen the news there new STD's & STI's that make any from the last 100 yrs look like something you'd be glad to catch ,you were very lucky it was one of the curable one's, some of the new one's are deadly ,incurable, flesh eating, cause sterility, leave scaring thru out the genitals and worse, always have and wear protection and don't shave the skin down there it leaves open micro wounds making it even easier to catch a STD or STI.

You hooked up before you got with your current boyfriend. It should not matter to him that it occurred before you got with him if he is an adult. That said you should have played safe if you are having a one night stand.

I would have been tested first. Then if it was positive. No need to bring it up if it’s not an issue.

Do you plan on sleeping with his entire family? Unsure why they need to know that you might've got something from someone before you were with your boyfriend