The Doctor was rather taken aback when the young man countered his argument for him to leave, arguing that he didn't want to go and that he wished to stay with him. Even though it was unexpected, the Doctor admired the young mans spirit and courage which he liked to see in people. He might not have been the most confident of human beings, but the Time Lord could tell there was something more to Leander than his image. Something more confident and something more keen. Giving in, the Doctor let out a long sigh. 

"Fine, but be warned, if we do end up meeting the Slitheen, they're ruthless and wont hesitate to kill you on the spot. Just let me do the talking, okay?" The Doctor told Leander before giving him a warm smile. "Allons-y! then!"