My Sexual Psychology teacher once told us in passing

My Sexual Psychology teacher once told us in passing that spartans durring the pelopenesian wars, went through the countryside and recruited young perfect boys for the army. once recruited the boys were trained in war and homosexuality. where is this information found?
to satisfy my question, you must provide sources that confirm that the boys were trained in both war and homosexuality. my professor said it was to ensure no one would run from battle.39628.7451266204