Went for spontaneous dinner with dsis and friend - they have met before and got on. I was supposed to just see dsis the friend asked if she could come for drink and hoped this would all be fine. Friend was friendly enough but can be cold/standoffish when she's doesn't know someone and this can come across as rudeness... I was making big effort but she was mainly talking at me and not dsis and it got a bit awkward. Dsis made her excuses to leave after an hour or so, but did leave earlier than she normally would have. Aibu to feel guilty?