<human>: Can you condense the text into a few key points?

This is the first year in awile we have actually been able to afford nice gifts for our mothers. I spent over an hour at a nicer clothing store and picked out two shirts for my MIL. Super excited; gift giving for her has usually been left to the hubs... Which is fine and great, but is pretty much always garden related bc it's a safe bet with her. 
Anyway, I hung the bag on the back of a dining room chair last week. It fell on the floor but between school finals week and starting a new job this week, it got left there, safely tucked away in a plastic shopping bag (or so I thought). 
Before work this afternoon, I grabbed the bag to get the shirts out to place in the gift bag. WET. WTF. Oh, that sweet petite kitty we took in out of a storm a few months back? She figured today was the perfect day to go into heat and piss not only on the two shirts, but also on the dogs bed. Lovely. 
As soon as this meowing, butt-in-the-air madness is over, said cat will be getting her lady parts removed. 
I currently have the shirts in the dryer after double checking the scent was gone per the washer and a baking soda/detergent combo. 
What do I tell MIL as to why I washed and dried and tags are removed? Do I just return the shirts? My only idea is to say that I wanted to wash/dry them for her to make sure they will fit right (she is a petite M-ish so may not be a stretch to think I would do this?...) but that is still weird. Any ideas?
<bot>: Cat peed on two shirts I spent a long time picking out for MIL for Mother's Day. Do I return them or give them sans tags after a good wash and make up a story?