Norwaygranny - lovely for you and exciting for him. My GC are almost all adults but come to see me when they can. Last weekend, two GSs drove over to see me and we went out together to the local lake for tea and cake. I see my DGGD often - almost 3, and taller and more talkative every time. A great joy.
Is it a good idea to put a photo of your DGS on here? Do his parents know you've posted it? Perhaps GNHQ could remove the photo for you if you decide it's not a good idea.
I never post pics of children on public forums. If you do a picture search on your phone, it's scary how AI recognises the faces, however much they change.
Have a lovely time with yours. I shall have some time with the youngest of mine who are 10 and 7.