Dude, You're an FO...
RV
Dude, does it matter? If the captain doesn't offer a first class seat, I bring it up and they always agree. If the jumpseater hasn't boarded yet (but we know he's out there), I usually go up to the gate to make sure he's getting on. When he checks in with us, I get up and go introduce him/her to the lead F/A.
You don't have to be a CA to treat OALs like that. If the CA is not being proactive, the F/O needs to be... good CRM, right?