LW, you are so far out of line, I can only imagine it's because your head is lodged too far up your own ass to have any idea where the line is supposed to even be.

Initially, they would both come and stay with us in the summers, but those extended visits have dwindled as they expressed interest in spending their summers engaged in sporting activities and at camp, which we have been supportive of.

Yeah, I just bet you've been supportive of their decision to go to camp instead of staying with you two. Why are you sticking this line in your letter like it makes you look good?

I mean, look. I'm sure those two girls really did want to go to camp. But they probably also wanted a father who gave half a damn whether he saw them any given year or not.

I would be left in a hotel room to celebrate with them at dinner after the ceremony.

Well, sounds like you guys can afford a high quality of hotel room, but if it bugs you so much, don't stay in the hotel room. Go to the movies, or the pool, or whatever. Or stay home and sulk for all I care.

I pointed out that her father continued to provide support above and beyond what he was required to even after we married (private school, camps, etc.) and that our household should be treated with equal respect.

Wow. Just, fucking wow.

I have always had what I would consider a friendly relationship with both girls.

Yeah, well, it's a graduation, not a wedding. You can invite everybody with whom you have merely a friendly relationship to your wedding, because you can have as many tickets as you like to your own big special day. For a graduation, she only gets five tickets.