This is the solution that I came up with for the bodybuilder problems where the size of jeans you want to fit into is 36, and your waist size is 30 or 32.
Wear a pair of suspenders. They look cool, even if you wear them as an undergarment or sport them on top.
Trust me, whatever you wear becomes fashion. A few idiots might make fun of you at first, but they will find it cool if you wear them everytime and feel confident about them.
They are so comfortable that i slept with my jeans on because I was too tired to change my clothes and it felt as if I were sleeping in my pajamas.
No more discomfort in the belly region while sitting on a chair, and no more messed up shirts when you tuck them inside :)