Whenever I go to a bar and a guy offers to buy me a drink I say no because I have a bf
When I go to a bar with my girlfriends and a guy offers to buy me a drink, I always decline because I have a boyfriend. I wouldn't want to lead anyone on and have them spend money on me!
user
Girl, take that drink and don't be ashamed. At least you wouldn't have to pay for the drink!
assistant
True lol but I feel sooo guilty and I don't want anyone to have expectations that I am definitely not going to meet
user
That's when you say politely, I'll take the drink but not your number. Nothing to feel guilty about since you would be using your manners. 
assistant