Oh come off it - this woman has sociopathic gameplayer written through her like a stick of Brighton Rock.
You're accusing OP of offloading, but ignoring the whole offloading weirdness of: "Pamela told me she dreamed I'd shagged your husband!"
& her reaction, both her "can't lose your friendship" & flip-flopping to "this is unsalvageable" is ALL about ramping up the drama & ensuring she remains Star of the Shit Show.
Not saying you were wrong to open up to her, but definitely could have been under better circumstances,
She ASKED OP what was up, so you can't go blaming OP for getting the timing wrong - she was pushed for a response while already upset & tipsy.
and I don’t think her reaction necessarily means something was going on -
especially after you clarified that there was no secret texting or anything like that.
No secret texting?! Only because OP didn't dig very far into her H's phone. Not that I think she should: she also doesn't need to as it's obvious - immediately after the confrontation OP & H had -
She then texted me and asked me "how do you feel" and I said "about what?" she then said "just checking in" and I responded "meh." She said she knew something was up and could I please tell her.
She didn't just intuit all that. OP's H told her all about it. Via text. Because that's what these two do.
See how we're all focusing on Sam? It's worked, she's created speculation even by proxy - imagine what turmoil & doubt OP is reeling through.
When really Sam is just a bit-player.
OP should be far more concerned about the fact that her H chose to snap at her all day.That's what I'd be tackling him about, because THAT is between them. Sam is just a distraction.
OP's husband is already acting according to The Script all cheaters/wannabee cheaters use - he's placing OP in the wrong by snapping at her, being irritated by her - over nothing more than the guilt he feels, which he is attempting to mitgate by suddenly deciding his wife is annoying him, therefore SHE is the one at fault, & he 'deserves' to indulge his 'friendship' at her expense.
This is the smokescreen beloved of cheaters who choose to use the Devalue cycle on their wives, so they can conveniently blame them for their underhand/lying/adulterous behaviours. OP - ask him WhyTF he snapped at you all day yesterday. Make it about how he is treating YOU, not about this ridiculous flirtation. Because he's going to do, or not do, whatever he pleases in that area, - you don't need to police it, all you need do is monitor how he acts toward YOU, & decide if it's good enough for you.