I was invited for a drink by a girl, together with 4 other people (classmates/friends). Normally I would gladly accept it and be happy about it. But this time I was very sceptical for the real reason to be invited. To make a long story short, I think the real reason to be invited was out of sympathy. I was excluded last time while everyone else was invited to come for a drink, and they knew I didn't like it. Anyway, during the drink things became more clear and I though it was better to leave. I told them I had an early appointment with my company the next day (no joke). So I took out my wallet and threw a bill of 20,- on the table. I made a good bye hand gesture and left without saying much.
So I'm wondering if paying the round was a friendly or a rude thing to do.