First, you don't have a big waist...at all. You have a small chest. What type of V-Taper do you expect with a chest that only measures 40"? Realize that some bigger guys could even get away with much larger waists and still look proportional because their chests and backs are so thick.
That is why Gunter Schlierkamp can walk around with a waist near 40" and still have an impressive V-taper simply because his chest is 60" around. With a 31" waist and a 40" chest, you are nearly straight up and down. Until you build up your shoulders, chest and back, it will remain that way.
Bottom line, worry less about your abs and more about building some actual size on your frame. God, a 40" chest is like what I had as a freshman in high school. How old are you?
Is anyone honestly trying to get a guy with a 31" waist to LOSE more weight? If not, why was every response trying to only focus on his abs?