"Where are you" sounds pretty legit and practical to me.
After listening to testimony in T1 and T2 it's clear they were invited to attend an after party at 34F. They had never been there before and they had been invited by the homeowner's sister. Thus why JO had to call Jen to get directions again.
John wasn't just dropped off. In my opinion or assumption he and KR agreed, because the house was mostly dark when they drove up, that he would go check if indeed they were welcome.
He was supposed to come out to get her or let her know by text that the after party was indeed happening. So, when he didn't let her know either way she first was frustrated but then became angry...like who wouldn't if their boyfriend just went inside and started partying leaving them to sit out in the car waiting?
In M00 she didn't really know these people so she wasn't comfortable just going in. Besides, if you match timelines, it appears a couple of people left during the time KR was sitting out there waiting for a signal from JO.