@savanahr777,

okay, he's exclusively boob anyways and if he gets any cups/bottles it'd be only water anyhow. but I figured since he does so good with the cup rather than the bottle when he's with family he couple get his feedings from the sippy to

As long as he is getting milk no problem that I know of the real issue is Baby bottle tooth decay which is caused by the frequent and long-term exposure of a child's teeth to liquids containing sugars. Among these liquids are milk, formula, fruit juice, sodas and other sweetened drinks. The sugars in these liquids pool around the infant's teeth and gums, feeding the bacteria in plaque. I know that's not really what you are asking but that is the reason Drs push to get babies off the "bottle"

Well he's only 4m. will that make a difference? @savanahr777

Great idea I did the same with my daughter she was off the bottle by 10 months just make sure not to give him milk in bed that's where the issue really comes from no matter if it's in a bottle or a sippy cup