I (22F) live with a roommate, we’re both broke students. About a week ago she cooked dinner for us. I immediately offered to Venmo her my share, but she said no and that I could “just treat her another time.” I figured that meant we’d keep things casual, but at least I made the offer. Since then, I’ve actually been super chill about other stuff. She lost her key once and I gave her mine so she wouldn’t be locked out. She also hosted a pre-party/after-party with way more people than she told me about. I was literally trying to sleep while strangers were in our place, but I didn’t make a big deal about it. Anyway, today she texted me asking if she could have one of my cans of soda. I replied that she could buy one off me (not in a mean way, just because we’re poor students and I try to keep food/expenses fair). She replied, “Well, you kind of owe me for that dinner.” I tried to play it cool and texted back something like “hahaha oh right, just take one.” Then she wrote, “Just forget it.” I reacted with a thumbs-up emoji to keep things chill. Now I’m confused. I honestly don’t mind sharing sometimes, but I prefer to keep it clear with money/food so no one feels used. Plus, I did offer to pay for dinner, she refused, and I’ve already been generous in other ways (keys, parties, etc.). So… AITA for asking her to buy the soda, or is she overreacting by holding dinner over me when she already said no to payment?