Has anyone experienced a relationship with an ISTJ? My mom (ISTJ) is in a relationship with an ENTP and she's looking for some insight into his brain and why the communication is so difficult sometimes? She says whenever she tries to have him express his feelings he will stonewall her...why is this? When it comes to his feelings he can never spell things out. He always leaves it vague. She wants to know why you ENTP's do this.