If you want to be kept in my dungeon you better prove your worth. A sub is useless to me if he can't take a whole cock down his throat. On your knees, I'm going to test you out. Not my biggest dildo, but big enough - you're going to be my little whore, sucking cock for money to pay for your keep. But of course I can't send you out on the streets until I'm confident you know what you're doing. A whore who can't suck cock is worse than useless. Let's see how you fare while I'm fucking your face. No gagging, just relax and let my whole huge cock slide down your throat.
Mmmm, not bad. There's more to it with a real cock, of course - I can't test how well you can swallow huge loads of cum. I guess some of my friends will just have to take your mouth for a test drive and report back. The way you took this dildo though I expect you're going to be quite the cum hungry little slut.