If you put two straws in your mouth, one inside a drink and one outside it, you won't be able to drink through either straw.

yes... because when you suck a straw you make a vacuum etc  and when there is another straw the vacuum gets filled by air.

 when you drink through a straw, your mouth becomes a vacuum pump,
lowering the air pressure in your mouth. Because air pressure tends to equalize, the now
greater air pressure of the atmosphere pushes down on the surface of the drink, pushing it
up the straw into your mouth. In this stunt, the particular available straw will keep people via being created some sort of
cleaner send along with your jaws. Hoover sends won’t do the job if they are not airtight. Your
straw is really a outflow in the program. Because stress within your jaws continues to be just like the particular
atmospheric stress, the particular take in stays on in the a glass.