What obligation? And most people who don't already practically worship him wouldn't believe him. If they did, they'd only panic, because right now he's not really reliable enough to pin 'save the world' on. Sure, 20 years, but people aren't going to think about that. Becoming some super great amazing hero who can save a whole world when you look like a submissive bumpkin isn't something people can think would happen in 20 years unless you were already BORN to be a hero, and already superhumanly powerful from day 1.
she looks cute even while riding him...
actually now that I've checked a little, is it not their first time together, since he wouldn't touch her as a slave?