That's funny, I had no idea POR was your initial resort - I just mentioned it because it was our favorite resort before we had kids and started staying mainly on the monorail for convenience - and got hooked!
I'm not sure on the best way to surprise him, I'll let others chime in because I'm sure they have great ideas! However, I wanted to let you know how our check ins have gone, just so you know it isn't always the same. Keep in mind we have never stayed CL at the YC or any Epcot resorts. In our 3x at the Poly once we were greeted at the front and taken on a golf cart to the CL building - but that time we drove and had all of our luggage. The other 2 times we took the magical express, once we had someone greet us with an ipad and take us to CL, and the other time we had to go into the lobby and find someone to take us. At the GF we took the ME, and no one met us off of the bus at all. We got our carry-ons and stroller and wandered in to the lobby and found someone to tell we were staying CL. Then we stood on the lobby for like 10 min while they tried to figure out what to do with us! Someone came and brought a welcome package to us that was some other family with the same last name! Finally someone just took us up to the CL floor to get us checked in, and it still wasn't all that smooth. At the WL I told them immediately we were CL, and we were with my MIL who was not CL, so they did take us right up and someone else took her to check in at the main desk. SO overall we have not been that impressed with CL check in. We still stay CL, it's not like it ruins it for us, but I keep waiting for the wonderful experience where they know we are coming and whisk us away and hand us champagne before they give us an upgraded room
. The closest we came was our very first CL stay at the Poly when we drive and got the golf cart. But I keep hoping, and my DH keeps making fun of me for it! But long story shirt, unless you get luckier than we ever did, he might not catch on until you are taken to a separate check in, unless you have to make a big production to get that separate check in and then he'll have to find out then! If all goes smoothly they will just say something about taking you to the club lever floor for check in, and you could let him know then, But there will be a CM with you, so it's not like you'll be alone to explain.
I don't mean to sound negative, we like CL so much we have 2 upcoming CL stays planned, but the check in seems to be hit or miss!