freeballing

I am freeballing today at work for the first time. Normally wear suit and tie, but it's business casual on Friday. Wearing linen pants with no underwear and no undershirt; I feel so exposed! I always freeball under shorts and jeans, by the way.

With suit and tie, I prefer an undershirt. I wish I could find a way to freeball AND keep my undershirt tucked in, since I use my boxers to keep it from riding up. I may have to resort to some sort of elastic band around my waist over the undershirt, but that seems ridiculous. Ideas?
 
Try wearing Jockey brand athletic undershirts XLT size. the XLTs are a lot longer and stay tucked into trousers.