I'm not sure where this belongs as there are elements of special concerns, relationship, adult kids....
The actual answer is - drop it for at least 6 months, but I guess because it's graduation season it keeps coming up. My husband I and I have been married for almost 20 years. We have a kid who is graduating high school next year. I have a step son who is almost a decade older, I've been in his life since he was 7. For background, his parents (my husband and ex) were married less than a year.
We all live a nonstop plane ride away from the DC area, but my stepson returned for grad school and will be getting his degree in a year. However, for his type of degree, he actually does a final internship year, so also won't be local to his school. For more context, although his college years were wrecked by Covid, he had a normal high school and college graduation which, of course, we all attended. Our daughter will be graduating high school next year as well.
My stepson has already begun asking that we make plans to attend his grad school graduation. It's a huge event, for the entire University, that takes place in a stadium and ends at 6 in the evening. He wants everyone to fly up from our respective cities to spend a weekend at the University location before he graduates.
So here's the big problem, our daughter graduates high school the next morning at 8 in the morning. He keeps bringing it up (I'm generally the travel planner in the family). and I said we really needed to just think about what makes sense, plus we can't even buy plan tickets for another month! He is adamant that he wants his sister there. But, honestly, it makes no sense to me logistically. If it was impossible, it would be an easy decision, but, theoretically, if everything went perfectly, we could get out to the airport just in time for the last plane flying to our destination and get home at about 1am. (assuming schedules are the same next summer - and this last plane is on a super budget carrier, so who knows.) I don't think my daughter should miss the graduation events with her friends and risk missing her actual high school graduation in these circumstances.
In my perfect world, he'd skip his graduation (and, for more context, I'm kind of biased here as I could care less about grad school graduations and skipped my own because I was already working - high school graduation just seems different as you are really leaving a stage of life behind.), and we'd fly out to spend a weekend celebrating his accomplishment the weekend before or after. Then when could also be together for his sister's event. In another world, less perfect but more fair, his dad could fly out for his graduation, and I'd stay in town with his sister, so she could do bacculareate. grad parties. etc. . They could try to make it back in time for the graduation itself.
I'm trying to let this drop, as he's started saying stuff like high school graduation isn't a big deal, so I don't think he's being rational. I'm really just trying to let his dad and him really think it through. By the time we are closer, he will have been working for 9 months away from school, class, classmates, etc. But it's come up enough times that I kind of need an outlet and some alternate viewpoints!