Shoutbox

Ok maybe im being thick here but need to ask something.
Both a friend and i have received invitations to add someone we have never heard of onto our messenger buddies.
Both invitations arrived at the same time.
He has never given his address out to anyone that we both know.
It just seems odd that we both receive the same invitation from the same person.  We live miles apart and only know each other through online.
Initially I thought it may be because we are both members of an msn group.....however I now find that the group has over 22 thousand members so ....its highly unlikely that someone would have tried to add all the members of the group!!! 
We have no other links other than that group and a chatroom where we met....but nobody there ever had his address.
Sorry I'm stabbing in the dark here...but anyone have any suggestions.
I thought  of maybe allowing the person onto my contacts just so I can quiz them as to who they are...I tried emailing but got no reply.
I know its no big thing, but I never get anonymous invitations on this address (for some reason I get them regularly on another address) - just wonder if someone is playing games with us both.

Is there any person who might have you both on his contact list? It is possible he exported his entire address book from MSN then imported it on another account which would send an invite thing to everyone he imported at the same time. I've just read the post again and realise it is very unlikely but I suppose there could be???