Dear Queenie,
When I asked a friend of mine whether she wanted to go to a certain event with me she said “no” because it would cost too much, but when I went alone I saw her there with someone else.
Queenie, why would she do me that way?—Offended
Dear Offended,
It is quite possible that the someone else picked up the cost of your friend’s attendance at that event. Assuming you could have afforded it, did it ever occur to you to make such an offer?
Tell your friend you saw her there and see what she says. You probably will know from her reaction whether you have reason to be offended.