OP here. Thank you everyone for the support. I really am just speechless. I may have to feign some sort of illness (from overuse of former coffee mugs) and skip spending time with her this Sunday.

I guess that's a whole other issue - I am fine with DH spending time with her without me this Sunday, while I stay home with the kids. Is that ok?

Who cares - that's what I'm doing. I think I'll take the kids shopping for new coffee mugs. There, I feel better already. Thanks DCUM!

Wow. Ask DH to buy you a special mug for this Sunday. Then every time your MIL comes over to your house, give her coffee in this mug. Tell her you threw away the mugs she bought because you hated them. If she gets upset, shrug and say you didn't think it'd be a big deal since she threw away yours.

Passive-aggressive for the win!

I hate clear glass mugs for coffee. we have them for water and beer.... but not coffee.

Your MIL sounds nuts. Glad your DH stood up to her!

I can't imagine drinking coffee (or any hot beverage) out of a clear glass mug.

Wow. Very glad your DH had that reaction - otherwise it would be much worse.

That is totally inexcusable.

On a self-serving note, I have a MIL who is the bane of my existence but this kind of story makes her look pretty harmless so thank you for sharing!

Good luck dealing w/ her.

Give her a lovely set of mugs on Sunday.

OY. A sane person might have mailed you a lovely gift box of new mugs, with a nice note explaining her health concerns about you. This is sick and over the top intrusive.

What?! Not ok. Happy to hear that DH stood up for you both. Nut job.

You have my empathy and sympathy because I have been there - except it was my mother and not my mother in law and my clothes and not mugs. You need to have a serious conversation with her about boundaries. This is an invasion of privacy. I wish you luck because this isn't going to be easy.

Go give your husband a giant hug and tell him you feel lucky to be married to a man who will stand up for you. And know that so, so many of us are not that fortunate.

This cannot be the first time this woman has done something insane.

Holy shit! Who does that!?!?!

Glad your DH let her have it!

Makes me glad that my MIL is in CA. Sorry to hear that, she is looney.

Also, you should change the locks. Just in case she made a copy.

I don't even know where to begin with this. I had about 10 coffee mugs - these were not a matching set. They are various mugs, accumulated over the years. I have a couple from college, Happy Mother's Day mug, other whimsical designs, etc. Last Saturday, I opened the cabinet to find that all of my coffee mugs had been replaced with clear glass mugs. I ask DH - he has no clue. We find out that his mother let herself into our house (she lives about 10 minutes away and has a key) without our permission, threw away my mugs, and replaced them. Her reasoning: the coating on my mugs cause cancer, especially when heated. She THREW AWAY my coffee mugs!!!

DH let her have it and took away her key. I honestly have no idea what I can do here, but I am still fuming. Though it actually feels better to vent here.