These tokens are from ancient Rome, and they’re called spintriae. They were only manufactured for a few years (perhaps as few as 15) in the first century, and they have no real intrinsic value, being made from brass or bronze.
Oh, and they depict sexual activity, rather than the more-common profile of an emperor.
All of that leads many people to believe that they were used as “tokens” in Roman brothels — you pay the cashier, then redeem your coupon upstairs.
But not everyone agrees. Both Salon and Cecil at the Straight Dope point to an influential 2007 essay byGeoffrey Fishburn called “Is that a spintriae in your pocket, or are you just pleased to see me?” (pdf).
He makes some interesting points — there’s no evidence of Romans having a token-based sub-economy in any area, let alone brothels; there’s no real correlation between the numbers on one side of the coin and the acts depicted on the other; Romans didn’t have the same hangups about sex that we do, so the coins may not mean much of anything; and frankly, it’s so far back in time that we may never be able to definitively say what they were for.
http://www.absurdintellectual.com/2010/04/05/brothel-tokens-from-ancient-rome/
PhotoAtelier Blog 
I have 2 that depict quite explicit homosexual acts and have no marks on the backs, I believe they are brass. I am very curious to know anything about them. They were found in CT and the man that would have had them was French-Canadian.
Hi Dena
Feel free to send pictures and other information about your coins so I can post them here, hoping to get a reply that might help you in your quest.
I contacted the museum of London and found out that they are 18th century and actually the first one shows a man getting an enema by a doctor and the second one shows the doctor watching the man relieve himself on the chamber pot. The finds liaison thought they had been buttons possibly but unsure of who would have worn them or why. I TOTALLY agree. I don’t know how to post the picture to your blog but maybe this information can help in my search.
How interesting! Well, if you wish, you can send to: photoatelier@hotmail.com , the pictures and a text with all the information you have, so I can post them here, and if you prefer, you can also add your contact so people can reply to your email.
I sent the pictures to your email. Did you get them?
Yes, I posted them with the text you sent.
https://photoatelier.org/2012/09/17/help-with-the18th-century-buttons/