Meh, unless you think spontaneous card games coincidences, not much happens in my school (Yes I know everyone in my year, since there is only 30 of us)
But CODMW2 is far too common of a game and I'm sure those girls probably own an xbox thanks to siblings. If you found a girl that played pokemon, that would be more of a coincidence, because COWMW2 is seriously overplayed.