Dougleo (Dougl/as and L/eo) is the pairing of a step-uncle and his step-nephew, which are Douglas Davenport and Leo Dooley. They started off as enemies, with Douglas trying to kill Leo for being a threat to his plans and Leo trying to get in his way to protect his family. Despite this, the two started forming a friendship in Taken and have become close friends over the time spent together.
Leo was the only person to believe Douglas was telling the truth and was trying to help them. Douglas knew Leo would believe him because he remembered how Leo was smart enough to figure out the truth about Marcus.
Douglas showed up at Leo's school to warn him about Krane, but Leo misunderstood and tried to fight him in vain.
Douglas use turn off Leo's bionics when he went to school to prevent him from using them and hurting himself or others, but had started training Leo to get use to his bionics so disabling them would no longer be needed.
At Douglas' (forced) wedding, he had chosen Leo to be his best man.
Douglas and Leo seem to have completely moved on from their past as they seem pretty relaxed around each other and tend to trust each other to a certain extent.
Douglas despised Leo at first, since he was onto him and Marcus and kept getting in their way. However, in Taken, when Leo is the only one to believe him about Krane, a friendship was born.
Douglas uses Leo to open up pickle jars for him.
He later begged Leo to open up a jar of pickles again, stating that he hadn't eaten all day.