Is it gross in your opinion?

It is disgusting. If you live with other people who also drink that beverage, it's even worse. If it's just for yourself, at least you aren't spreading germs, but it's still a disgusting habit to get into. You might forget yourself and do it at somebody else's home some time. Also remember that the outside of beverage containers can be a minefield of germs. They're handled dozens of times by different pairs of hands during shipping and stocking shelves. If it's a beverage that can be kept at room temperature it becomes even worse. Soda cans often sit in a warehouse for several months before they are shipped off to a retailer. During that time mice crap and pee on them, different hands are touching them, and then we come along, pop that silver ring on the top and drink straight from the can !! Beverages ideally should be poured into a gl for drinking - the outside of any container is totally germ-covered. It is suggested that soda cans be washed before they are opened so that the filth from the warehouse and people's hands can be washed away before popping the top and letting all that stuff drop into the soda.