Day 4 as a Stay-At-Home Parent

I'm not sure if I mentioned that my wife has recently gone back to
work after close to 5 years of staying home to raise a family.
Although it's under 20 hours per week, she's excited to go back and says it's
a good change. I'm happy if she's happy.

This means that I take care of the kids for those days that she's at
work. Day 1 was scary and my main concern was making sure I provide a
good explanation when they start asking for mommy. I've been saying
that she has gone to pick up more waffles at Shoppers Drugmart or that
she had to go get more eggs at Costco. This worked and they have been
content with that but on Day 3, I think my eldest suspects she's
really just gone back to work.

One thing that someone brought up the other day was in the incorrect
use of the term "babysitting". He made a mistake of saying that he was
babysitting his kids and was reprimanded because technically,
babysitting means you have to hand them off to someone after your
shift. If they are your kids, you never get to hand them off, so
technically, it's not babysitting but "taking care" of your kids.

Since wife has the car and it's too cold to be going outside, we have
to fill our time with activities inside the house. Currently this
includes:

- Breakfast;
- Netflix on TV, iPad;
- Watch foot/car traffic outside;
- Arts & Crafts;
- Snack;
- Bubble bath;
- Lunch;
- Angry Birds game;
- Youtube on PC
- Read story books;
- Nap;

Any suggestions on what one can do on a lazy day to bond with their kids?