UPDATE: AITAH for setting a deadline on my GF to tell her family about us?

Original post: https://www.reddit.com/r/AITAH/comments/1vga0gs/aitah_for_setting_a_deadline_on_my_gf_to_tell_her/

A couple of people messaged me asking for updates, so here goes: To the surprise of nobody, she didn't tell them. Instead, the night before she was going to she told me that she'd decided it would be "too much disruption" for them before they left home for university and she didn't want to unsettle them or risk her relationship with them in their first term.

Instead, she presented telling them at Christmas. Her current mortgage ends in January, so she said we could tell them, put their house up for sale and then move in together straight away. Obviously, as hard as it was, I declined, restated my boundary, and walked away from the relationship.

She has fought me tooth and nail on it for days and is still accusing me of abandoning the relationship and breaking promises because I "didn't get my own way" over a "temporary timeline change". The problem is, it's a "temporary timeline change" that I can't trust wouldn't happen again and again and this seems to be the part she isn't grasping.

Truthfully I don't believe her that she would tell them then either. To me her excuse makes no sense - why would telling them be more disruptive now than telling them that not only is their mother in a new relationship but their house is also being sold 12 weeks later? If anything it's more disruptive because it's two massive bombshells in a shorter time period for adjustment. At no point could she give me solid assurance or explanatory answers for my questions either, and most of the time when pushed she just reacted with defence and pretty much word salad.

Thank you to everyone who commented. A lot of the commentators helped me see things really clearly, and I even ended up using some of the comments in my explanation to her and although it's really hard, I'm pretty sure I've done the right thing.