That is actually almost exactly what happened with me for the last game jam I joined with my partner! For years my partner wished for me to join him on a game jam and make art for a game. Last Easter we made our first game, this one is our second and I have pushed myself to make some of the 3D-models, as well as paint and design them!
I am very happy to hear you have had a good experience so far with game jams, and hope to possibly see some more beautiful games from you and your fiance! <3 :D