The following article contains an answer for the question: Who does Alfalfa's sweetheart leave him for? , can you please find it? 

Spanky McFarland is the president of the "He-Man Woman Haters Club" with many school-aged boys from around the neighborhood as members. Alfalfa Switzer, Spanky's best friend, has been chosen to be the driver for the club's prize-winning go-kart, "The Blur", in the upcoming Soap Box Derby go-kart race. However, Alfalfa is nowhere to be found.
The boys go to find Alfalfa and discover him in the company of his sweetheart Darla, with whom he is forbidden to be in love because she is a girl, which goes against club rules. Alfalfa invites Darla on a picnic, and to prove his devotion to her, he agrees to have the picnic inside the clubhouse. Unbeknownst to Alfalfa, his fellow club members find out about his plans.
At the picnic, Alfalfa and Darla think they are alone, but the other club members secretly pull several silly pranks to sabotage their romantic date (whoopee cushion, cat litter in sandwiches, etc.). When they finally reveal themselves and demand to come inside the clubhouse, Alfalfa frantically tries to convince Darla to hide in the closet, which leads her to mistakenly believe that Alfalfa feels ashamed of her. In the frenzy, a candle flame gets out of control, ultimately causing the clubhouse to burn down.
Darla breaks up with Alfalfa and turns her attentions towards Waldo, the new kid in town whose father is an oil tycoon. Because Alfalfa burned down the clubhouse and also fraternized with a girl, he is assigned by Stymie to guard the go-kart until the day of the race.

Waldo