This is not tested, but should give ya the idea...
PHP Code:
$uservoteinfo=$DB_site->query_first("SELECT userid,voteoption FROM pollvote WHERE userid=$bbuserinfo[userid] AND pollid='$pollid'");
if ($uservoteinfo[userid]==$bbuserinfo[userid]) {
$options=$DB_site->query_first("SELECT options FROM poll WHERE pollid='$pollid'");
$poption=explode("|||",$options['options']);
$opnum=intval($uservoteinfo['voteoption']) - 1;
$yourvote="You voted for " . $poption[$opnum];
} else {
$yourvote = '';
}