lateroses replied to your post “Question for the trivia types: When was the last time Sam and Dean...”
The Purge kind of qualifies from s9? When Alfonso tells Dean to stop flirting with the yoga instructor/Sam.
larinah replied to your post “Question for the trivia types: When was the last time Sam and Dean...”
The kids in Bitten made a bunch of comments about it. So at least early season 8. (There may be some instances since then, though.)
So it's probably one of these two, depending on how you want to read the thing in The Purge - did he really get a 'gay couple' vibe from them or was he just poking Dean with it? (I also had an anon mention Crowley speaking of Sam as Dean's wife, but that seems to more clearly fall into the 'poke' category).
Basically I was wondering whether they'd dropped that trope on Sam and Dean as they turned up the romantic subtext on Dean and Cas... and so maybe they didn't drop it altogether, but toned it down?