You shouldn't expect people to pay for your purchases.
Jane is out having drinks with friends after work.
Jane wants to enjoy the night.
Jane follows her friends up to the bar as they order their drinks in turn and pay for them individually.
Jane tells a friend what she wants to drink when the friend goes up to order a drink for themself.
The friends enjoy their drinks, the atmosphere and the evening together.
Jane's friend complains that Jane never pays for her own drinks and the mood is ruined for the evening.