Make sure to spit shine it.

"Oh, nice, so you've finally pooled the money from your many lovers to get one ring. Good thinking."

Some bitches need to learn what tact is

You should've told her it was a fake ring, would've been even better if the new husband actually got her fake diamonds.

Sounds like she is still in control of your life

What a major bitch supreme!

I'm not sure why this is **** your life. You did a job, he on the other hand agreed "Till death do you part." **** his life.

You could have refused service due to conflict of interest.

What #3 actually meant was to shitshine it

if she cheated on you who cares? you apparently dodged a bullet. make the new ring look nice.

To play devil's advocate, we do not know just how long these two have been broken up. Does it suck that she cheated? Yes. Is it uncomfortable to see an ex when things have ended badly? Yes. It is, however, possible that their relationship ended a LONG time ago. Obviously, it has been long enough that she got engaged and then married. He says she is vindictive, but there is no way to know if that is true without hearing about vindictive things she has done in the past. If she had wanted to mess with the OP she could have shown up and made him clean her brand new ENGAGEMENT ring. She didn't. When she got engaged, messing with OP wasn't on her mind. If this was some sort of plan, then it took her until however many months/years after getting that engagement ring to get her wedding ring, and then decide to be an asshat to OP. To me, this feels fairly implausible. So, how new is the "new" ring? That day brand new? Less than a year new? Or just new to OP? She may have showed up at the jewelry store the ring was purchased at to get it cleaned/polished and OP just happened to work there. I take all of my jewelry to the store it was purchased from to get cleaned. It's covered by the warranty, and therefore free. Taking it elsewhere can cost money and they aren't usually able to do as much with it. If it is the store that it was purchased at, then she and her new SO likely went to the store two or three times to pick out the wedding rings, get them sized, and pick them up. OP has likely not seen her during any of these occasions or cleaning it wouldn't be a shock. This means that she likely didn't see him there either. She just showed up to get her ring clean and there was her bitter ex. Awkward. What is she supposed to do? Leave and drive however long to another branch of the company to get it cleaned to spare OP some awkwardness? Leave and come back another day? Or maybe hope that OP is mature enough to just do his job and get the awkward situation over with. Cheating was shitty, and if she somehow came intentionally to flaunt it, that is shittier, but there is no way to know that at moment. TL;DR: Relationship may have been YEARS ago, and the EX probably didn't know OP worked there. More information is needed.

If she has to play petty games with you, her life can't be all that crash hot...