Mindtext

When you text someone back in your mind, but not in reality, because despite the fact you formulated a response in your mind, you subsequently got distracted by something else and forget to the respond.

Sorry Brian, I mindtexted you earlier but then forgot to text you back in reality.

Mental relationship defect

Similar to a mental defect, but applies to intimate relationships, particularly when one party takes subtle steps to sabotage a relationship.

Tom: I thought you two were getting along great until she flipped shit over you ordering fettuccine instead of linguine and then insisted on taking everything to go for leftovers.

Jerry: Yeah, that girl has a mental relationship defect.