This game was working out perfectly! She'd lost nearly every round.

When she'd thought it was getting out of hand, she'd asked to change it up. Given the option to stop playing if she won the next round, she lost yet again, forfeiting the right to stop playing until she won a round.

It was all down hill from there -for her. For you it was a big win.

She'd have to say "Yes" to everything.

Obviously she'd put up a fight, explaining why she couldn't. Don't bother trying to convince her that it's not that bad, or that 'nobody has to know', as so many like to say. It's too cliché. Rather, simply explain that she must make the request you were demanding of her.

"Yes, of course I'll take my top off, since you asked me to", while regretting the fact that she'd never be able to take back the visual she was giving you for your personal spank-bank.
"Yes, I'll give you a blowjob for a quick minute.", putting in her mouth another man's cock for the first time.

"-as long as you don't cum in my mouth." she added. She wasn't really allowed to go adding stipulations, but it wasn't as though you were going to cum in only a minute, anyway.

Since she was adding a stipulation of her own, you'd add yours.
"Blow me for a minutes. I'll even give you three, but if you can't make me cum you've got to make me cum -in your mouth, AND show me."

She was disgraced by the idea.

"Will you make me cum in your mouth, if I don't cum?"
"Yes", she'd regrettably say, proceeding to give you head until you erupted with excitement!
She'd felt so bad as it happened, feeling like she'd betrayed her husband, whom she'd never allowed to cum in her mouth before.

Now, having shown her tits, to his friend, and given you head, she had to play another round in order to win and stop playing these silly games.

She lost. Not again. What would you ask for next?

For her to use your dick as if it were a dildo?
-she'd never even rubbed her pussy before, let alone used a dildo herself.
-of course she'd have to use it until she came, regardless of who came first.
Those were just the rules.

For her to become your very own pocket pussy?

How many loads could she take before she was certain to become pregnant?
What would she possibly say to her husband?
She never let him go without a condom!