Stuttering only when I am in my comfort zone!!

Stuttering only when I am in my comfort zone!! Hey guys, Ok so I am really very puzzled and annoyed at myself. I used to stutter a lot since i was a kid but since last few years my stuttering has drastically reduced... to the extent that its not even noticeable. People are surprised when i tell them that i stutter. Here's the annoying part: I only stutter when I'm talking with my family members! Parents, siblings and wife. This is a piece of the puzzle that im not able to solve. I dont stutter with the rest of the world. I now only stutter with my family. Why does that happen? Here's my theory: I stutter the most when I am in my comfort zone. When I am around my family, i am in my comfort zone.. and hence is stutter. Here's an example to prove this: At the time I got married (3 years ago), i wasn't stuttering with my wife. But now, 3 year later, i am in my comfort zone when im around with my wife... so i have started stuttering even with my wife!! ​ I am not in my comfort zone when im around with my in-laws...and guess what... in the three 3 that i've know them... i havent stuttered even once with them! All naturally... i don't "try" to control my stuttering or something... i just don't stutter. ​ So... can anyone solve this puzzle for me please?? ​ I really need to crack this phenomena. ​