M.D.
When you are not with him perhaps drinking from the side of a cup would work. We did that at 5 months and it was the only way we could give her something to drink when we were not around. I instructed the care givers to just give her a cup like you might give someone a drink who was too sick to get up or something like that?? Caregivers would inevitably try other things first...bottle, sippy, etc but just drinking from the side of the cup (with cloth underneath to catch spills) was the only thing that worked. Good luck and it kind of sounds like he might be able to eat a little more food, too. I know when I was trying to cut back on bfing refusing and offering food instead was helpful.