To find this a little irritating?

[butwhiletheresmusicandlaughter]

First time poster but long time avid reader...
In summary, recently renewed a long time friendship
with oldest school friend- always kept in touch very
sporadically via email etc over the years but in the
last 6 months we've seen quite a lot of each other
and got much closer again- it's been lovely.

Friend has met SIL twice in total- once at family
event and again at a New Years get together at my
house. They seemed to get on ok but did not
have any in depth conversations. Should
add for clarity that SIL is same age as us and
totally lovely- we get on really well.
Friend sent text this morning saying she had
been talking to SIL on the dreaded facebook
and organised for the three of
us to meet for lunch one weekend in the next few weeks,
and wanting to put a date in place.

I can't really even put my finger on why this bothers
me. SIL has a lot of her own friends who she socialises
with regularly. I am very rarely invited to any events/
Get togethers with SIL and her friends, and nor
would I be expected to be. I guess I just like the
fact that I do have my own friends, all be it a small
number, but close friends none the less.
Friend doesn't really know much about SIL,
and for all she knows we might not even get on
that well socially.
I think my issue is that I like keeping friends and
family separate, if that makes sense. After all, I
can hardly let off steam and have a rant about
DH or MIL in front of SIL...
I guess my question is Aibu to feel a little put
out by this, and if not, how should I deal with it?

[Sirzy]

You can't stop your friend from being friends with your SIL. It is nice they are trying to involve you in their planned meet up so you don't feel left out

[R4roger]

perhaps they think 3 is an easier number, little less intense.

[gobbin]

Life's really too short for this sort of emotional angst. Meet up, have fun, celebrate the fact that you all seem to get on and do it repeatedly! You're trying to control something that is not yours to control (who is friends with whom) and is wasting your brainspace.

[IAmAllImportant]

I think it's nice. Your friend is obviously on the look out for friends, and has seen potential in your SIL!

[Lj8893]

I get your irritation at this, i have a similar issue, although i know it may seem petty or minor.

i hardly ever see my "best" friend anymore even though he seems to see sil frequently (according to Facebook, i know i know!)

i was really quite upset and bitter about it at first, but just busyed myself making new friends and over it now.

[DecaffCoffeeAndRollupsPlease]

I get what bothered you about this. Unfortunately you can't change it so, it's best that you enjoy the change in friendship status for what it is. I understand the need for a friend who is outside of your family, but you'll have to designate this role to someone else now.

[R4roger]

perhaps the SIL instigated it

[Purplepoodle]

Completely irritate me too, though I know it incredibly childish to want to keep a friend as just my friend it's just exactly how I would feel BUT I would shove it all down and go and have a nice lunch.

[MagicMojito]

Its totally unreasonable but I'm exactly the same. When I used to socialise I'd go to great lengths to keep everyone in their own little "boxes" family with family, friends with friends, work people with work people etc. It caused a lot of stress and angst. There really isn't much you can do about it though.

[butwhiletheresmusicandlaughter]

Thanks all for the abundance of grips (no sarcasm here- think I just needed some unbiased opinions to gain a little perspective). You're so right gobbin-life is too short to worry about such things. Guess I've broken my New Years resolution to not worry about unnecessary things already...