DIY Green Sippy Cup

Ok so I have tried many different sippy cups. The only one Levi, my son, knows how to drink from are the ones with straws. Well they have started growing mold in places I cant get too. I've tried leaving them in bleach over night and ... nothing. So I saw on Pinterest how to make Mason jars into sippy cups! But then I started thinking.... While this is nice and green and inexpensive I'm still giving a toddler glass so I bought on EIO Sleeve. They were a little expensive... But fit perfectly on a half pint jar.

I used a 1/4" drill bit so I believe the grommet size was 3/16"? (I took in a straw to make sure I was getting the right size.) I'm sure I looked funny carrying a straw into Ace Hardware...

You might want to file the edges of the hole down because it will a bit rough. This is where I had my husband feel helpful. I let him put the grommet in. :)

When putting the straw in I got it a little wet and bent the straw in a bit. I actually trimmed the straw because the 1/2 pint cup was smaller than the straw.

 The Total Cost: 12 pk of 1/2 jars = $10.71 which comes out to $0.89 each and the grommets were $0.34 each. $1.22 TOTAL!!!

Update: After using thisfor a little bit we've run into a small problem. It is so leak proof that there is not a continuous way to suck which frustrates Levi. I think I'm going to have to make another small hole for air to come in through and put another grommet on it so he doesn't hurt himself.

Has anyone else run into this problem and how did you fix it?