I think you can use a night owl, or a night-person.
I think a sleepless man is fine. Another similar word is an insomniac (a person who suffers from insomnia), but I believe that you know it already.
Actually, what you describe sounds pretty much like me myself. :)
Sometimes, people called me a vampire, a batman, or a dark knight, which is not quite to my taste. In casual chatting, I personally prefer a night dweller or a man of the night more.
Here is an excerpt from Wikipedia's page Night owl:
A night owl or evening person is a person who tends to stay up until late at night. The opposite of a night owl is an early bird, a lark as opposed to owl, someone who tends to begin sleeping at a time that is considered early and also wakes early.
As a native speaker, I wonder: is the problem with the water, or with the bottle?
That said, a few expressions come to mind. The first one is the most direct:
You might not want to drink from that bottle; Ann already had her mouth on it.
The second is more of a euphemism than a scientific fact:
Don't drink from that bottle – it has germs.
(We don't know for a fact that the water has any contaminants, but the word germs is often used to refer to unseen microorganisms that could spread disease, particularly in informal speech.)
Because the concern is mainly with someone else drinking from the bottle, you could also say:
Be careful! That may have someone's backwash in it.
TFD labels this definition of backwash as "informal", while the Urban Dictionary says:
Backwash is often created inadvertently or unintentionally when liquid escapes the mouth during the process of drinking .. When multiple people drink from the same container, there will usually be some amount of backwash put back into the container.
As a footnote, the adjective for drinkable water is potable, though anyone who would deem bottled water as non-potable simply because someone else drank from the bottle is probably using extreme hyperbole, or else is an overly sensative germaphobe.
Best Answer
I don't think there is a special term for that in English, but if we're talking about public places like shopping malls, restaurants, hotels etc., you could always refer to people who park their cars by themselves as self-parking customers: