Complex sentence: Horrified at the realization that he turned her down for a date, he uploads her altered photo to the Internet, and prepares to ask her out, but finds out that she and Clyde Donovan are now dating.
Split into simpler sentences: Horrified at the realization that he turned her down for a date, he uploads her altered photo to the Internet, and prepares to ask her out. He then finds out that she and Clyde Donovan are now dating.