He didn't offer any details. They were unnecessary. Hermione vaguely remembered there being a major scandal not too many years after the war ended with him getting involved with young Astoria Greengrass. The witch had only been out of Hogwarts for a year or two. Despite the change in his circumstances following the end of the war, the feelings she had for him from their time together in Slytherin were still very much alive. They wanted to marry, but Astoria's father wouldn't allow the match. He wanted something better for his youngest daughter than a Malfoy. When they tried to elope, they were caught and a more suitable husband was found for her instead.