Randal enjoys the attention he gets from Dwayne, even though he knows it’s wrong. He knows something is off with Dwayne but has never had someone who loves and truly cares for him the way Dwayne does. As time goes on, the feeling of uneasiness and fear grows stronger. The closer Dwayne gets, the stronger the feeling is.
He loves the feeling of being someone's favorite, being thought about, being talked about. Although he knows it's unhealthy for both him and Dwayne, he doesn't put a stop to it.
This is partly why Randal stays with Dwayne after the forest. He likes the idea of someone needing him. He feels sorry for Dwayne and wants to help him, even though Randal himself is the issue. With Randal gone, Dwayne would get better, but Randal doesn't want to leave.
He likes the power he holds.