Dear entirely different author from my previous post (although this is in the same fandom, and indeed the same pairing),
You, unlike EDAFMPP(ATIITSF,AITSP), definitely did need a Brit-picker. I have work in an unhealthy amount of hours, so need to head to bed soon, and after the first part of your fic, I gave up, skimmed to the bottom, read your author's note WHICH ACTUALLY INCLUDED ANOTHER BRIT-PICKERY ISSUE, WTH, so for all I know, there were more issues, but these are all I have to comment on at the moment.
a) the modern kilt, as worn to weddings ( and other formal occassions, or everyday), in Scotland, where your story is set? Yeah, not so much with the old school 'it is so difficult to pleat it in the apparently very specific way that you will need someone to help you with it' thing. Indeed, you just wrap it around yourself and buckle the buckles. It is that easy. I know this a) because I live in Scotland, and have extended Scottish family b) I'm not blind and c) I just typed 'how do I put on a kilt' into google, to make sure what I thought was right, is in fact right. Also, the very idea that the character you're putting in the kilt, supposedly Scottish, would have reached the age where his friends are getting married and wouldn't be able to get himself into a modern kilt is a joke. He would have likely been forced into one more than once as a little boy for family weddings and the like, may have worn one to school parties, would almost def have worn one to various university balls (esp as you've had him attending uni IN SCOTLAND)....it is inconceivable that he would need help with this, the way you have set the story, is what I'm saying here.
(if you meant an old school belted plaid / great kilt, you should have said so....but I highly doubt you did, given the rest of the description, which brings me to my next issue...)
b) It's called a sgian-dubh, not a dirk, and it is worn tucked into the kilt hose (with only the top of the hilt visible), not the belt. If, for some reason, you've decided that your char is not wearing traditional highland dress to the wedding in this story, you need to have made it more clear. Dirks can be work with kilts, although, given that they tend to have a foot long blade, they are not tucked into a belt, but rather, hang from a special strap from a dirk belt.
c) d'aw lookit your character going on about stereotypes of Scottish people. Cute. Esp when compared with the RIDICULOUSLY broad Moira MacTaggart wheest ya eejit (and yeah, it's eejit...edjit, as you have it, is more Irish than Scottish) type accent you've given the father of the groom. Not everyone in Scotland has the same accent, and people who, according to you, live in a castle and have a title, do tend to talk a bit more posh, like, and a bit less broad than your character. Although, what do I know? It is entirely possible that they are not in fact Scottish at all, and you've got a whole backstory for him that explains why his name is what it is. I've certainly never met a Scotsman who uses that particular shortform of that name. It's either 'full name' or 'first syllableIE', here, in my experience, not just 'first syllable'
d) I've tried not to make it obvious which story I'm talking about, (note the clumsiness above! When i could have just said the names and short forms!), but I can't, not with this next issue. You've made the father of the groom 'Lord Selkoe' "because it was the closest [you] could get to 'selkie'" That's nice, but I can do you one better. Selkirk. It's a real place, in The Borders. Google. It is your friend.
okay, I feel a little mean now. But it is late, and your story made me grumpy.