Do you mix friends from different friendship groups?

[Framce60]

I did once and got severely burnt. Now, friend A has invited herself to something with friend B, and I feel very uncomfortable about it

Why are you so uncomfortable? Surely the worst that can happen is that they don’t get along?

@IfThen because of the past , although neither of these friends were involved in that

OK, but unless you’re more specific about whatever ‘the past’ means, no one can know whether it was some life-altering catastrophe or whether you’re exaggerating. And as you say yourself, neither of these friends was involved in whatever ‘burnt you severely’.

Yep, all the time.
And have the pleasure of watching new friendships spring up between them.

No. Did it once and it was awful. I have different friends for different things and they don't combine well!