DS is 5 and in reception, he is very close with his best friend in class and told me this week it was his birthday. Last night at 9:58pm his friends’ mum text me to say she’s having family and friends over with bouncy castles and slides for a party and asks if my DS wants to come over to play for a few hours for the next day. To me my son was a complete after thought considering how close we already know they are and how late I’ve been told. Plus we do have plans for part of the day - weather permitting- but had I known before I would have made sure he can go. Am I wrong for declining the invitation?