The day your Master/Owner locks you up in a chastity device and tells you to forget about touching, getting erect, or even cumming for the near future.
You're turned on for a bit right from the get-go and you probably get resoundingly fucked then fall asleep in each others arms.  You wake up a few times with some burning or pinching.  But, you feel good about living out your destiny of being locked'n'denied as skavecto a Apha male Master!
That's the easy part.  Then ...
After a few days you start to miss touching, fondling your cock or as you now think of it your clitty  You miss that exciting feeling as it grows semi stiff in your hands.  And you say to yourself "God, I wanna cum."
You figure your Master and keyholder will be back on the weekend and he'll let you out.  He'll perhaps let you stroke your cock hard and bust a nut whilst he's fucking your hole.  But Friday night comes and he's tired from working all week and he just wants to have a nice meal, some cuddling and a good night's sleep.
Laying in bed, spooning with him, you reach behind to feel his cock because you miss the feeling of yours.  Even though he's tired, his cock responds ... hardens in your hand.  It's then that your cock suddenly swells in the cage ... almost hurting.
He turns to lay on his back and you turn and duck under the covers.  You hold his hard cock at the root and bring his swollen, hot, soft cock head to your lips.  You breathe in the smell of him.  Your tongue darts out to touch the tip to find he's already oozing.  You open your lips and let his cock slowly enter your mouth.
You start to suck his cock slowly, respectfully ... as a beta slut should enjoying the feel of it as your throat relaxes and more and more of it slides deeper down your throat.  There's a deep sigh from him.
As you suck him your cock swells and fills every bit of space in your cage.  Your hole twitches and your mind suddenly screams in need.  You want to leap up and drop yourself on his pole, rape yourself on him.  Your body desperately needs release ... you've never gone this long without cumming. Even when your Mistress trained you and locked you!
You're now a good sub slut boy and you focus on his cock. You feel it thicken, harden.  He's moaning now. His body squirming.  You suck harder. You feel that tube in his cock swell.  He grabs your head with both hands and fucks your throat.
With several ecstatic grunts his load explodes in your mouth and you swallow every drop.