Back in high school the guys' pants could fit an entire 2L bottle without it being obvious that there was anything in there, while the girls' skirts and dresses couldn't even fit a bus ticket.
How baggy were those pants ? Because regardless of pocket size, a 2L bottle is just... noticeable.
I have shorts I use at festival that can fit 0.5L in the pocket easily (and somewhat comfortably), but it's still pretty obvious I have something in my pocket.
Pretty loose, but not exactly baggy. The inside pockets were large enough that the bottlecap would be barely showing out opening, so with a little bit of leaning the bulge would just look like some slack.
I can hide 2 1.5 liter bottles in my hoodies, I just don't have to hide anything anymore... so... eh.
Basically I'd cradle them like an inverse "T" with both my hands in the middle pocket, cradling the bottom one, with vertical one on top but inside my shirt as well, so it doesn't lean too far forward and produce a noticeable bump, then as I'd walk I'd slightly hunch over so it just looked like the slack in my hoodie was hanging forward just due to gravity.
I have shorts I use at festival that can fit 0.5L in the pocket easily (and somewhat comfortably), but it's still pretty obvious I have something in my pocket.
Basically I'd cradle them like an inverse "T" with both my hands in the middle pocket, cradling the bottom one, with vertical one on top but inside my shirt as well, so it doesn't lean too far forward and produce a noticeable bump, then as I'd walk I'd slightly hunch over so it just looked like the slack in my hoodie was hanging forward just due to gravity.