I trust you're in a bedroom and not a roomette. Three adults in a roomette - that would be the very definition of cramped - visions of a clown car at the circus come to mind.
If your son can't join you, dining is no problem. If an unreserved meal, simply show up at the same time and ask to be seated together. If it's reserved, make a reservation for him along with you. He'll have to pay, but I'm sure you were expecting that.
You'll have to ask the SCA if he can join you in the bedroom. You might want to respectfully point out that Amtrak
will book three in a sleeper and that he's paid his full fare and make sure they know he's your son and will be just visiting not sleeping. They may be able to do something for you, if not you can always go back to the sightseer lounge or, if there are empty seats visit him in coach. If the SCA says no, please don't hold it against them, they may be working under a stickler
hboy: of a conductor and value their job.
Personally, last February Mrs SP&S and I had a bedroom on the Starlight, LAX to PDX. A couple of weeks before we left we bought our daughter a ticket EUG-PDX on the same train. Early in the trip, we talked with our SCA, somebody from the extra board who normally worked coaches, and politely asked if we could have her join us for a while. She was a little reluctant at first (of course we pointed out that she was paying more for her coach seat that we were for out AGR bedroom) but she said she'd see what she could do. Later on she said she could, and to have her board directly into our car. Of course I had to get out in Eugene, find my daughter, and lead her to the car as the gate personnel were directing her to a coach - thank heavens Eugene is a smoke stop. I figure she wanted her to board directly into our car to avoid hassles with any other of the crew.
We stayed in our bedroom, figuring that the three of us hanging out in the Parlour would have been pushing things :blush: , and had a wonderful ride. Dinner is served after Portland, so that was not an issue.
De-training in Portland our SCA - who otherwise hadn't earned a big one - was rewarded with a very nice tip in the handshake and a "thanks for taking care of my Daughter". I always have figured that
extra service deserves an extra tip :hi: .
Whatever, enjoy the trip.