Complex sentence: As a teenager, he had a crush on Axel von Fersen's mother, Hedvig Catharina De la Gardie, and in 1768, had a deep emotional attachment to the noble Charlotte Du Rietz, although is is not known if their affair was ever consummated.
Split into simpler sentences: As a teenager, he had a crush on Axel von Fersen's mother, Hedvig Catharina De la Gardie. He was in love with noble Charlotte Du Rietz in 1768, although is is not known if their affair was ever consummated.