The original script gives us a pretty good idea of the order of events;
JACK: Excuse me, George?
Jack checks his watch and hands Hammond a piece of paper.
HAMMOND: Colonel, what are you doing out of uniform?
JACK: Handing you my resignation [He hands a letter to Hammond]
SAM: You're resigning?! What for?
JACK: [looks at watch again] So I can do... This!
[He takes her face in his hands, and kisses her on the mouth. She
starts to put her hand up as he puts his left hand around her neck.
His right hand is at the small of her back. He dips her, moving his
left hand to the side of her breast, and his right hand a little lower
... Somewhere in the kiss, he slips her the tongue, (I think it's when
his face is turned right before he dips her) because she starts to
respond by putting her arms around his neck and the way their mouths
are moving, they are definitely kissing open-mouthed!
[A blinding blue light appears]
Light shines in Sam's face, making her blue eyes seem bluer. Sam's
SAM: What are you smiling at?
JACK: [smiling] Nothin'
Clearly he timed it so that the 'time loop' would occur during or immediately after his attempt to kiss her, knowing full well that this was his opportunity to indulge a fantasy with no consequences.
Given that Teal'c wasn't in the room at the time, the only person who would know about the specific events would be him. The implication is that he doesn't plan to tell anyone. Certainly there are no canon instances of his discussing it with any of the SG-1 team.