"Let's go to (pub) for new year, it's comic con themed."

"OK, I'll wear my Iron Man outfit."

"Actually, I don't feel up to going out. I'm just gonna stay in with my housemates."

"Well I have an invite to my best mates, and it's walking distance."

"I'll just see you on the 1st"

Then today

"I'm going out to the comic themed night because a friend is coming out"

I'm moving into a bigger house with this girl in two weeks. Can I get a quick shake about sunk cost fallacy?