This is my first post on here so apologies if this is in the wrong place.
My son is 6.5 yeas old and was diagnosed with ASD aged 4.5 years old.
He's high functioning but since his little sister is getting older (she is now 3) some of his issues, namely being first, are getting worse. She copies his behaviour which adding to the problem. We have constant arguments about who is going first in and out of the front door. He cannot cope with not being in front walking to school so constantly runs off ahead. My daughter is also copying this behaviour which adds to his frustration. I feel like I am having to shout after him like some kind of fishwife as he runs off, with his head soley focused on being first ignoring my instructions. Making him hold my hand results in a meltdown and him trying to control how and where his sister is walking.
I've tried a social story with no effect, he flatly refuses to use any sort of reward chart for this. Most issues he is semi of flexible on but not this.
Does anyone else have any suggestions on how to deal with this behaviour?