A third option?

You feel torn between the discomfort of tucking and the prospect of being caught so easily. Maybe a middle road?

"Does Becca have any thing else in her bag?" You ask shyly, pulling your clit out of your panties.

Samantha tapped her chin, "hmm, let's go have a look."

She grabbed your hand and pulled you along back to the bag. You fall to your knees and rummage around, before coming across a plastic bag with a pair of steel chastity cages inside. "Would these work?" You ask Sam, holding up the bag.

Your sissy girlfriend's eyes widen, "that looks fun! You want to lock up your clit?"

You blush, nodding, "Yeah, keep it hidden."

Samantha smiled, softly pushing you onto your back and pulled out one of the cages, the smaller of the two. Pulling down your panties, she slid the cage over your cock, the cold metal causing it to shrink even further to fit in the metal nub. The hinged ring followers suit and then your girlfriend locked the cage in place with a definitive click.

It was over before you even knew what hit you, and as Samantha pulled your panties back up, your diminutive cock tried to expand, only to be crushed inside the cage, arousing you almost as much as it pained you. You panted, feeling a tightness in your chest at the sensation, Samantha leaning forward to kiss your open mouth, wrapping her tongue around yours.

She broke the kiss to speak, "that's so hot, locking your clit up like that, I almost want to do that to, but I love feeling my clit throb."

You look at the bag, the remaining cage is much larger than yours, "you could still throb in that one." You point to it.

She looks at it, rubbing her chin with her finger as she grinds her ass on your newly caged clit, her own cock hard and dripping above your stomach, "hmm..."