Because let's face it, teenagers have done stupider things for love.
+Snoke encouraged the possessive, dangerous side of their love to fuel Ben's descent into the dark side
++as a result Kylo and Poe are very jealous, very possessive, like flirt with one of them and Kylo will go in a jealous rage while Poe will gut you while smiling for touching what's his
+++Hux finds them both incredibly annoying while Phasma doesn't give a shit
Poe/Kylo, when Ben went to the dark side Poe went with him
+Snoke encouraged the possessive, dangerous side of their love to fuel Ben's descent into the dark side
++as a result Kylo and Poe are very jealous, very possessive, like flirt with one of them and Kylo will go in a jealous rage while Poe will gut you while smiling for touching what's his
+++Hux finds them both incredibly annoying while Phasma doesn't give a shit