when i worked at holiday inn we added gratuity to groups of six or more. some people in these groups would try to get around that by paying separately. this is not a loophole. if you are sitting together and obviously together, separate tickets or not, the auto gratuity applies. the server is waiting on a large group no matter how the total gets split. it takes more time and is harder and she is missing out on other tables, that quite frankly would probably be more lucrative while waiting on you.