"Yeah, sorry, can't come to this work related thing that's happening in my spare time, because, I have other plans."
It's still true, even if those other plans were to sit on the couch in your underwear and binge on Netflix and chocolate.
You basically described my plans with that. :)
They're pretty good plans. They'd be my plans too if I had curtains and netflix. I have to settle for pyjamas and Torrents
I do have curtains, but they're rarely drawn. I'll walk around in my underwear whenever I want. If people have problems with that, then they shouldn't be looking in my window. :)