I agree with divine1966. You need to let go of having an exact time for your partner to call your son while he is away. Stop. That is not the real issue here. The real issue here is that you are refusing to go with the flow with your autistic son. My autistic nephew is forced to go with the flow b/c of his parents' and siblings' lives. It's taken him years to adapt but he has, and now he no longer punches, kicks, screams, or bites. But that is only because my sister and her husband and two children were patient and worked with my autistic nephew to show him how to adapt to stressful situations and circumstances. Have you tried to do that yet with your son? Autistic children NEED their caregivers to show them that skill. They need it. If they aren't given that skill, they will be harmed by the world, esp. the government system set up to benefit them. I am a staunch supporter of autistic people and I hate it when I read a caregiver's account such as yours, who refuses to be flexible for the sake of their autistic child. You can't control anyone but yourself. Stop this obsessing about this stupid wedding accommodating you. It's not going to happen. Stop berating your partner. Stop threatening him. It's not his fault what his friends do. Just stop it. He's not being selfish. He's been put in the middle by you, and is being manipulated BY YOU. Just stop it!

You are definitely setting up your son for more distress by putting such rigid expectations on your partner and your partner's friends to accommodate you. These people getting married are focused on themselves as they should be. Why should they accommodate you? So, they haven't been upfront with your partner about the ceremony and reception times. Again, stop obsessing about that and instead, focus on teaching your son how to adapt to change b/c when he gets older, if you don't teach him those adaptive skills, you are setting him up to fail. My autistic nephew used to be rigid and would have HUGE meltdowns until his family caregivers showed him how to adapt. Now, he at 16 he doesn't fly into rages anymore. He knows how to ask for help and he has buddies at school who help him in regular mainstream classrooms and teachers who help him and parents who compromise their rigid belief systems and routines to help my autistic nephew.

This is your chance to stop being rigid and to work with the circumstances you've been thrown by these friends of your partners. Stop wasting time arguing about the stupid times and start problem solving how to deal with your son's separation anxiety that you've done before. Or you are setting yourself and your family system up for a totally un-necessary negative outcome b/c you refuse to let go of your rigid expectations which is causing you, your partner, and your son grief that doesn't need to be.