So. Thong, brief, boyshort, bike short, head to toe body suit. Let me provide you with the T-Rex's guide to selection of riding undergarments
Are you young? Slender? Not yet working on the sitting trot? Not yet read the classic equestrian literature, Riders? Think that VPL* is a fate worse than death?
Are you in pursuit of that smooth, almost hermetically sealed look regardless of age? Breathability be-damned? Think that every lump and bump, in addition to VPL, must be conquered?
Are you less young? Perhaps you have a bit of a tail to contain? Started working more on sitting the trot and canter? Have you read Riders?
- Then you will probably have opted for the brief/boyshort** option for two major reasons:
Because when you are out there on a jumping course, you don't need to feel either the 'letter in your mailbox' or the sudden and highly distracting draft.
*VPL = Visible Panty Line
** Seamless is worth the investment to avoid similar abrasive qualities in nearby delicate regions