Sorry, this is terribly long but I don't want to drip-feed.
Bit of background:
DS is 6 and in year 2 in MS school. He is still waiting for an official diagnosis but he has major sensory issues and either severe dyspraxia or ADHD (or both). Despite his SN, he's really popular at school and is achieving at average or above average levels in most topics.
He has been pretty close friends with 2 other boys - A and B - since the start of year 1 but because I worked FT last year (although don't anymore), he has had very limited playdates with them. He's been to A's house a few times and A has come here but he's only been out to play with B once. A recently moved away, meaning that DS and B have become even closer.
Now to the issue:
It was B's birthday recently and DS kept talking about how he'd been invited to B's party but no invitation was forthcoming. I kept telling him that he must have got the wrong end of the stick, that although it was B's birthday, not all children have parties etc, but DS was adamant. I humoured him until the day before the 'party' when another parent asked me if DS was going to B's party. It was really awkward because everyone knows that DS and B are such good friends.
Given that they are such good mates, and that my DS loses things all the time, after a lot of thought, I texted B's mum the following morning and said that DS was under the impression that B was having a party that day and was invited.
She didn't reply for hours and eventually said that it was a very small party with just family 'and a few close friends'. I thought that was a bit 
but thought that maybe the friendship was a bit one-sided which is why DS wasn't invited. The following week at school, B tells DS that he hadn't invited DS to his party 'because my mum doesn't like you'. DS was pretty unfazed by this and I just laughed it off (I just reiterated that it was a small family party).
Few weeks on and DS is badgering me to invite B over to play. So I've texted his mum and she's not replied. It's 2 days since I invited B and she might of course have changed her number but I suspect she just doesn't know what to say. I checked with the class teacher this morning to see if the friendship was actually one-sided but no, she told me that they are inseparable and the only issue is that they're a bit giggly together.
So I suppose B's mum really doesn't like DS. :( DS is kind and sweet-natured. He's a bit silly and can be a bit loud and hard to manage in busy situations but he's basically a nice kid.
WWYD if you were me? I can't decide if I should speak to her (it's quite difficult because she doesn't do many pick ups or drop offs, it's usually a relative) or just let this be a lesson to both me and DS that some people are pretty shitty when it comes to SN.