–no-existing-session is is a handy little parameter, as documented by –help:

jani@saegusa:~$ LC_ALL=C totem –help | grep no-existing
–no-existing-session Don’t connect to an already-running
instance

Totem’s man page however fails to mention –no-existing-session altogether.

jani@saegusa:~$ man -P cat totem | grep no-existing
jani@saegusa:~$