We have now gone through about 10 sippy cups since Leo learned how to drink from them. If there’s one piece of advice I can now offer to other parents of toddlers, it’s this: stock up on sippy cups.
Either they get misplaced, left behind someplace, or the little stopper thingy in them gets lost, rendering them useless. (Sure, your tike can still drink out of a stopperless sippy cup, but your couch will smell like sour milk the next day).
You tend to realize you’ve lost a sippy cup first thing in the morning when you’re cranky, your kid’s cranky, and you need to give him something to drink to quiet him down while you get his breakfast ready. At this point, the last thing you want to do is crawl around amongst the Lego pieces and noisy electronic toys, looking under furniture and between cushions for a sippy cup that will no doubt have curdled milk in it when it turns up.
So stockpile sippy cups for such emergencies. It will make you a more pleasant person in the long run.