Doggtyred
En-Route
I hope to be briefed on this. Fun it will be yes. I debated not bringing one of them but then thought "why not" - it is fun to share flying with others. Plus they get a free airplane ride.
Your briefing: climb rate will be less at gross weight than at lighter weights.
Tip: make sure you know where the pilot isolate switch is on the intercom. Sometimes a plane load of pax get chatty on the intercom and you may need the silence at key points suddenly and without forewarning.
I unfortunately had to throw the switch on my mom once because I missed an ATC call.