I've been saying the same thing in thread 31 and/or earlier about why she wants the vacation with Matt before all of the weddings. Other reasons she might want the vacation with Matt before the other weddings:... The real reason why the trip is in may and not september, she wants that engagement happening before all the upcoming weddings. Italy... a lake... churches... proposal at the lake and afterwards burning a thank you god candle in one of those chapels;
1. She wants to come to an agreement with Matt as to how to answer the inevitable question of "Why aren't you two married yet?" She needs to coach him so that his answer will jive with hers. She will practice her learned coaching techniques on Matt, and ask variations on that same theme to test him. (The correct answer, of course, is up to her, no matter what she comes up with for marriage excuses!)
2. She wants to have a recent, glorious trip somewhere so that when she and Matt are asked 'the question', she and Matt will easily divert attention to "Guess where we were last month?". Then, she will be able to brag all she wants about her trip as a convenient pivot from the marriage questions she and Matt are likely to get.
Of course, if he proposes, then her answer will be 'Look at the 1 carat diamond ring Matt bought in Italy for me!"