AITA for going on my phone at a table I was at with my girlfriend’s family?

My girlfriend “Katherine” and I have been dating for about 5 months. Her family is one of those clans where everyone grows up and lives in the same small town their entire lives. And everyone in the family sees each other a few times a week. Katherine and I live in the city. I see her family once or twice a month. They are very religious.<br><br>Katherine and I went to church with her family last weekend. After church they asked if we would like to go out to eat with them. I said yes. It was Katherine, myself, her mom, her dad, her younger brother, her older brother, and her older brother’s wife and their infant daughter. <br><br>We got to the restaurant, sat down, and ordered our food. Katherine went to the bathroom and her older brother’s wife changed her baby. One of Katherine’s brothers talked about how his job is going, and I watched the baby fidget. Then Katherine returned and I excused myself to use the bathroom before our food came.<br><br>I went into the stall and as I was about to sit my phone started ringing. “ Incoming voice call from… MOM”<br><br>I didn’t answer it because I was about to pee, and it stopped ringing. But then it immediately started ringing again. So I thought something terrible happened and answered it.<br><br>My younger brother, who is 8 years old and my mom’s “caretaker” for the day (my parents divorced last year and my dad moved to a different state) fell out of a tree because he had never climbed one before and didn’t know what he was doing. My mom can’t pick him up right now because she’s getting radiation for stage 3 brain cancer, and my dad has “ committing suicide by cop for no reason” disorder, so I’m the only person available to pick him up from the hospital. <br><br>I left the restaurant, drove to the hospital, took care of the whole thing, and my dad decided to come back to town to stay with my brother for a few days. It’s 8 pm now, and I haven’t heard from Katherine or her family the whole time.<br><br>I figure at this point they probably went home. So I call Katherine to tell her what happened and explain where I was. She says that they finished eating dinner and she exclaimed “where’s my boyfriend” and her dad said “don’t worry he’ll be back, he’s just on his phone. He’s a good kid.”<br><br>I tell Katherine that my brother was in the hospital and she tells me that I should have just told them I was going to the hospital instead of just leaving. I tell her that I was in the bathroom when my mom called and that I didn’t receive the call until seconds before I had to leave.<br><br>She says it doesn’t matter and I’m rude/immature for going on my phone at a table and not telling her family where I was going. I tell her that I would never intentionally stand her family up and that this was an emergency.<br><br>She says fine, but I‘m still rude for using my phone at the table. She admits that it wasn’t until I didn’t come back from the bathroom after 20 minutes that they were all worried.<br><br>So AITA for taking the call?