No doubt you've done this at some point:
You're at an event or user group and find yourself chatting with someone new. A friend of yours strolls over and joins the conversation. Being the polite person you are you introduce your friend to the new person. They reply with 'oh yes, we already know each other - Bob here is my brother...'
Easy to feel embarrassed right?
You shouldn't - in a healthy group or event this should be happening all the time.
These days I make a point of introducing people whenever I can. I'd estimate that on 20% of those occasions they already know each other.
Far from being embarrassing it is actually a good thing.
Don't apologise, instead follow on with something like this: 'Oh good, just checking. Have you known each other for a while?' etc - use it is a conversation starter. (Of course, if they are brothers, you may want to use a different line... )
Why? Because it really is embarrassing if you chat for a while and then the third person takes it upon them self to make the introductions. Or worse, they part ways never having been introduced.
Some caveats
Obviously you should use a bit of common sense.
- Introductions are best via a question: 'John, do you know Cathy here...?'
- Don't go introducing people who clearly recognise each other (eg they are already chatting :-)).
- And don't go out of your way to introduce people who are in a hurry eg they may be just passing by to quickly mention something to you.
- Oh, and be careful introducing people if one of them is very well known (eg 'Tim, let me introduce you to Bono...'). Famous people - at least those worth being introduced to - are usually gracious and take the initiative of introducing themselves. Which is why you'll hear things like this at a developer user group: 'Hi, I'm Scott Guthrie, pleased to meet you...'
Forgetting people's names
We all do it. Don't try to hide it.
If you obviously recognise them, and think the chat is going to be more than a passing hello, then bite the bullet and 'fess up. A simple 'I'm sorry, I've completely forgotten your name...' is better than dancing around the 'good to see you mate' routine.
And if like me you've been in situations where you chat with them later at the same event and you've forgotten their name again, just 'fess up again: 'I'm so sorry, this is embarrassing, but I've forgotten your name again...' - they may be a little peeved, but that is still better than them realising via your use of 'mate'.
What's the point?
User groups, events and other community gatherings are about getting to know each other better.
So, focus on the good of ensuring everyone is included, and less on the etiquette and social dance that can otherwise detract.