At that time Lyre's parents didn't know that he was in a relationship with Dwight so he told them that they don't need to worry because he already has someone in the ninth army.
Fortunately he didn't say he was capable of group guiding. He didn't say what he is capable of to Dwight because of the security reasons for Lyre. He didn't want Lyre to be endangered so even though Dwight was already his boyfriend at that time he didn't say anything else. The fewer the people who knew Lyre's ability the better.
If he said anything to Dwight at that time he might still be deceived until now just for his ability. He knew that his so-called family was very greedy. Once they knew he had that ability they would use him for their own gain again. They would have used his relationship with Dwight to tie him up with the family. So it was really fortunate that he didn't say what he was capable of to Dwight.
