Nana's Cocktail Meatballs

1 bag frozen Italian-style or homestyle meatballs
2 cups ketchup
2 cups grape jam
Lemon juice, to taste (maybe 1/4-1/2 cup, to make the sauce tangy)

Mix ketchup, grape jam and lemon juice in a sauce pan over medium heat until combined.  Add frozen meatballs and cook on medium-low until heated through. 

This can also be prepared in a crock pot.