J.W.
My son refused to drink milk out of a sippy also. We gave him a cup of milk at each mealtime with a straw and held the cup for him at first, until he could hold it on his own without making a huge mess. He loved drinking milk out of a straw. Then when he got a little older, we got rid of the straw and he just drank out of a cup. That was also around 18 months of age if I remember correctly. Then we got rid of the bottle at night by just getting rid of it. One night we sat down to read stories and he was expecting his bottle and he didn't get it. He cried a little bit, but he still went to sleep like normal, and 3 days later, he stopped expecting it. It usually takes 3 days to create a new routine. You might have an awful toddler on your hands for 3 days, but then it will get a lot better and then he will forget about the bottle like it never even existed. Is this a 3 day weekend coming up for you? You could start tomorrow and then have 3 days before you go back to work. It's important not to give into what they are asking for and stay strong, now matter how much you want to give it to him. Good luck!