Here's my geeky gaming analogy for seduction:
Gambits are magic spells, fundamentals are core stats.
Gambits are powerful tools that can turn the tide of the battle (seduction). However they are situational, must be transitioned into carefully, and can only be used once.
Fundamentals, on the other hand, are your core stats that will carry you through all seductions. By leveling them up, you become stronger overall.
He isn't bitter , remember...just indifferent
His investment is lower relative to hers just like in the beginning
If hers drop,his drops too
Some part of him is still interested but he isn't chasing
And that's attractive to her
He still stands a chance(hate putting it this way) of getting her