Love cheating on Joe is the most out of character thing

The way I see it, love if so obsessed with Joe to the point of killing anyone Joe is interested in as with Natalie. But what I don’t understand if she is this obsessed and even in death saying they’re perfect for each other, why is she cheating on him. It’s not just sexual it’s also emotional which is what some claim is what’s going on. I believe Love killed Delilah because she believed Joe had some feelings, obviously she did part of it to protect Joe but I believe a part of her truly didn’t want the competition. Which still makes me wonder why would she cheat on him if she’s that obsessed with him.