Do not add water

My husband and I use the same hair gel. I don't really mind--it's a good brand and we both get the results we want. But we do have one problem. My husband is a diluter.
As you probaby know, hair gel is kind of thick. For the first half of the bottle, you just tip it upside down and squeeze. But once it gets past that halfway mark, you have to give it a little shake before squeezing. A big green blob of gel detaches itself from the rest and sort of plops down to the opening in the bottle. One shake, no big deal. The bottle's clear, too, so you can see just how much you have left.
The thing is, once we get down to the bottom, say one eighth is left, somehow that big shake just doesn't work for my husband. I don't know what the problem is. One big shake still puts enough gel down to work with. But for some reason, once we get down toward the bottom, my husband adds water. He says it's just enough to loosen it up and make it easier to get to. Except that's not the case. I've tried his watered-down product before. Gel is sticky. This stuff is just runny. I can feel a difference in my hair. It doesn't hold as well. You see, he dilutes it. He weakens it. Why would you do something like that? I know all about trying to get that last little bit out and being thrifty and all that. But if you weaken it, then why would you want to use it anyway?
My husband occasionally tries to add just a little bit of water, thinking I won't notice. Why would I not notice? Again, it feels different and it doesn't work as well. Now I think he adds water as his way of telling me it's time to replace the bottle. I noticed last week we were getting a little low. Then, sure enough, Friday we suddenly had about a third of a bottle again. So I tossed it and pulled a new bottle out from under the sink. No weak product for me! Give me full strength every time.