O.C.D.D (Obsessive Compulsive Douchebag Disorder)
You're stuck on a lover who is a total piece of trash. They're a lying, cheating, selfish disaster, but you still believe they're perfect and you take them back every single time.
'He cheated on me, but I still took him back.'
'He left me for his mom. Still, I took him back.'
'He stole my dog, but he said he loved me.'