In the end, I completely forgot about the missed phone calls and messages when I woke up the next day.
I got up around noon, and went to the kitchen to make myself some coffee. The girl I slept with last night was still asleep, and I let her be for now. She wasn't in my way, so there was no need to wake her up. I reheated the breakfast that the boy prepared for me before going to work, and watched some videos on the tablet while eating.
While I was sitting by the kitchen table eating breakfast, I heard rushed footsteps coming from my bedroom, followed by the front door opening, and then closing quietly. The girl must have finally woken up. It seems she was reasonable enough not to expect anything else, and just saw herself out. Or maybe she was being shy, after how she acted last night when drunk.