The mechanics I have in mind is similar to a lot of dicepool systems. Lets say you have the following stats, apart from the skills and stuff (which are fine):
Virtue - Defensive stat
Desire - Offensive stat
Arousal - Equivalent of HP
Permanent Virtue+Desire always equals six. This is the amount of virtue points and desire points you may have. They are replenished in some way (can be discussed)
Tests are done dicepool-y. Roll d6, success on 4+, count successes. You can spend a point of virtue or desire to gain additional success or reroll. You can spend only one of each per turn and cannot spend both on the same roll. You can spend Virtue to resist temptation, help others and so on. You can spend Desire to tempt others, obtain something, etc.
Arousal goes from 0 to 6, unless modified. If you reach 6 arousal, all you want is to fuck and you don't have much control over yourself if any. Arousal attacks are successful if they score more successes than the defence. Then they give you the difference of the successes as arousal points.
Alex wants to seduce Bess.
Alex has 2 Virtue 4 Desire and is at arousal 2
Bess has 3 Virtue 3 Desire and is at arousal 0
Knowing her fetish for alternative boys, he appears dressed in gothic clothes and makes a vamp roll (3 dice for skill), gets 2,2,3=0 successes and spends a point of Desire to reroll. 5,6,1 = 2 successes
Bess uses threat to defend (2, -1 for the fetish) and rolls 3 = 0 success. Spends a point of Virtue for an additional success, so she can partially resist. She still gains 1 arousal.
Now it is her turn, she uses chastise (2 dice)to tell Alex to stop slacking and start doing his part of the project, instead of trying to get in her pants. She rolls high, 5,6 = 2 successes and spends another virtue point to go to 3.
Alex defends with threat, (1 dice), rolls 3, but even if he rerolls, this is still a loss. He spends no desire, shuts up and goes to his place for a while (time frame is intentionally described vaguely, as in the book). May be next time he'll have better luck and Bess will be a tad more aroused.
And pretty much that's it.