maybe add some checks so it dont say the same nick twice or say the bot\'s nick...
heres one way...

on @*:text:!orgy:#:{
  if ($nick(#,0) <= 4) { msg $chan Sorry $nick You Need At Lest 4 Other People Not Including $me In The Channel To Use This Script  }
  else {
    :pickagain
    var %nick = $nick(#,$r(1,$nick(#,0))), %nick2 = $nick(#,$r(1,$nick(#,0))), %nick3 = $nick(#,$r(1,$nick(#,0)))
    if ($istok(%nick %nick2 %nick3,$me,32)) || ($istok(%nick %nick2 %nick3,$nick,32)) { goto pickagain }
    if (%nick == %nick2 || %nick == %nick3 || %nick2 == %nick3) { goto pickagain }
    else {
      msg $chan $nick starts an orgy!
      .timer 1 3 msg $chan $nick grabs %nick %nick2 and %nick3
      .timer 1 5 msg $chan OH NOES!
      .timer 1 7 kick $chan $gettok($nick %nick %nick2 %nick3,$r(1,4),32) YOU GOT AIDS! 
    }
  }
}

or

n @*:text:!orgy:#:{
  if ($nick(#,0) <= 4) { msg $chan Sorry $nick But You Need At Lest 4 Other People Not Including $me To Have An Orgy  }
  else {
    :pickagain
    var %nick = $nick(#,$r(1,$nick(#,0))), %nick2 = $nick(#,$r(1,$nick(#,0))), %nick3 = $nick(#,$r(1,$nick(#,0))), %ohno POOP SHOOT,MOUTH,EYE SOCKET,ASS
    if ($istok(%nick %nick2 %nick3,$me,32) || $istok(%nick %nick2 %nick3,$nick,32)) { goto pickagain }
    if (%nick == %nick2 || %nick == %nick3 || %nick2 == %nick3) { goto pickagain }
    if (%orgy) { halt }
    else {
      set -u8 %orgy on
      msg $chan $nick starts an orgy!
      .timer 1 3 msg $chan $nick grabs %nick %nick2 and %nick3
      .timer 1 5 msg $chan OH NOES!
      .timer 1 7 msg $chan $gettok($nick %nick %nick2 %nick3,$r(1,4),32) YOU TOOK IT IN THE $+($gettok(%ohno,$r(1,4),44),!)
    }
  }
}