My name is Mastiff and I'll be reviewing your piece. These are just my thoughts and forgive me if I ramble, and realize I make just as many mistakes as anyone else. Thank you for sharing your writing, and I hope this is helpful!
Title: I had to laugh. As soon as you say something like that, it's sure to be worse. So, I'd say it fits the story to perfection. It's would be a decent reader draw, but even though I do it as well, sometimes using the subtitle will draw even more people. Consider a dropnote or popnote to add the contest rules.
Initial Reaction: I generally read a bit, then decide if I'm going to review. This is part of I Write 2020, so it's not an option. But you had me at man cave, and then add in the craft room? Oh my, did those hit home! I enjoy flash fiction, so I most likely would have done it anyway, but still...
Setting: I know it's very hard to set a piece with a short word count, but do think about the five senses. I say this as much to remind myself as anything, but it really helps create the space if you can manage it.
Character Development: Are they young or older? What do they look like? Yes, it's only 300 words, but try and fit in some descriptors of the people in your story. A little goes a long way in that regard!
Plot: It's a new take on an old theme, really. Listen to The Bickersons someday, and you'll realize couples arguing over stuff isn't really new. However, the "man cave" and the new version of the craft room, the "she shed" are certainly of late.
Ending: Whups! A little too late! As I said, as soon as you say what you did in the title... your character tempted fate! And you know how she can be!
Line-by-line and Suggestions:
Para. 2 Ln. 2 - The hyphen is okay, but in a conversation, a period would work just as well.
Para. 7 Ln. 1 - Consider dropping the second "at work." Ending after "week" might make for a better flow.
Overall - Not bad! Very good technically!
Adherence to Contest Rules: Everything looks fine, almost... but even though it's not required, a word count is nice. Not only for the contest but to anyone reviewing the work. I did my own and it was 301. I just like to know because it factors in how much room you might have to add to the story.
Overall Opinion: It was a fun read, especially since it hit so close to home. Of course, I'm not sure the door to the craft room can still open it's so packed with stuff!