Well someone was looking out for me.

She just came back onto FB from her mum's place and said that they are not going to the grave as she thought it would be best to wait for her partner to get home, so he could go too. So once I know they are home I will make sure I am straight over collecting him from his 2 day sleep over.

I'm glad I wasn't totally over-reacting for not being asked first. Had I been asked, I would have said "I'd rather him not go, I'll come and get him"