Since Kylo spent some time in Poe's head they have a one-way connection that Poe has no idea about. Kylo wanted to use it to spy when he can find the time and the quiet to concentrate on infiltrating Poe's mind, but as the sessions go on, Kylo ends up being less of a mental spy and more of an obsessed viewer of a cheesy romantic holodrama. Basically, he starts to shirk his duties in order to tune in to the will-they-won't-they show of Poe Dameron and FN-2187. In fact, he even mysteriously starts to ROOT for Poe and Finn to get together. (Let's face it, Kylo Ren is a dramatic shipping fangirl at heart.)