Spot on, PhilaGardener, the seed grown last year had to be already crossed. The cross didn't show in the F1 (last year's) because red and regular leaf are dominant traits.
If last year's fruit were strictly cherries, ie had only two locules (seed cavities) then the cross was probably to another cherry. Small size and two locule fruit I believe is technically 'dominant', so a cross between a cherry and a larger fruit will have a small fruited F1, but some of the size related traits are dominant or 'penetrant', LC or locule number for example can show up in the F1 as a small fruit with more than two locules, depending on other shape genes present.
Growing out crosses is a lot of fun, always full of surprises.
