Since when the tip was added to the bill!? Isn't that the customers discretion, what if server wasn't worth the 20 percent your so freely add on to bill

Most restaurants DO add gratuity to the bill if there are 6 or more people on one bill. You can usually request the gratuity NOT be added, however if it is posted on the menu ahead of time, some places will stick with that. Either way, officially it IS gratuitous and when you get your bill, you can request it be reduced to a lower amount and explain why.

Did a takeout someone else paid the bill

Some one else paid the bill so i did not see the bill.