Different sets of Rules for running out of spoons between Dad and I?

It seems a bit unfair for two related people (parent + child) who both have some form of ASD to have two different sets of "rules"  for when leaving a person's house when they're eager to get going for X, Y,Z reasons.

I'm don't like the fact that Dad and I have to have separate 'rules' for leaving other people's houses. 

For instance if I'm stuck  at someone else's house and there's more then just us (Mom, Dad and I) we can't leave until someone else leave (with exceptions like: the other person staying over)- and I will be quiet cranky if we been there since like 2 or 3pm in the afternoon and not leaving until about 7-9pm at night because it means I'm haven't been on my computer for most of the day because I'm in the next town,  or I'm miles, miles, miles, miles, away from the computer (family gatherings) and that makes me really grumpy if we been there for too long.  I  only have so many spoons to deal with a family gathering and I start to run out of steam by after we have dessert on the table that I need to leave the table before I explode at the table.  

Like the last time we had a family gathering- after Aunt M left (she's always is the last one to arrive but the first one to leave)- and i asked Mom when WE would leave but she wanted to "look at the yearbook a bit more" (its the only yearbook my grandparents could afford from the school my Mom and her siblings attended)- and I was getting so tired of being there, I literally had a meltdown-because I had basically run out of spoons.  I mean maybe Mom could ask Uncle J to borrow it to take home so she can look at it for a couple of months and bring it back to Uncle J the next time we have a family gathering?  Just anything to get me home sooner then we did get home (not until 11pm at night).   And since I can't drive, my Dad is the only one to get me to and from the house.  

Due to my sister's car troubles, my Dad went  to visit her along with Mom today   and last night Mom said depending on conditions where my sister lives,  that by 3pm or so- that Dad will be loosing his spoons, and be anxious to get back on the road to get back home before it gets much worse and hopefully no accidents are on the high way.

it just seems unfair that Dad loosing his spoons means he gets to leave sooner from some place but yet I can't even if I'm running out of spoons at family gathers or at my Dad's friend's place and just want to GO HOME.