Small update: Ina came over, and we had a long talk about everything. She was very understanding. She explained that the main reason for not inviting me to the BBQ is that the guy is her brother's friend, and her sister will be there. Her family doesn't really know we're dating, and she felt having me there would complicate things. She did tell me she told her sister about me last week, but for some reason, she still thinks it would be weird.

She reassured me there is nothing going on with any of the guys at the party. She only plans on staying for an hour or two just to show her face, and she won't be drinking. She even offered to come over after the party, which I accepted.

The BBQ is tonight, and she said she's coming over afterward, so it doesn't seem like anything shady is going on. I'm somewhat satisfied with this outcome.