<human>: Can you give me the gist of the text in a nutshell?

So I'm visiting a friend tomorrow, haven't seen him in a long time. We're just going to hit some bars and pubs. My GF is a bit clingy and expects from me that I'm available all the time (even though she does what she wants). Also she has a few borderline disorder symptoms... The last time I've visited him, I made the big mistake to answer her messages all the time. My friend was quite pissed (I know I've acted pretty rude and I've apologized).
So this time I want to leave my phone at his apartment while we're on the road.
How can I explain it to her in a careful way? I don't want to lie and say something like "oh my phone died, I've left it at home to charge it".
<bot>: Want to have a good time with a buddy but my GF feels like I'm leaving her alone just because I don't text her all the time.