So imagine this: either Dean or Cas nearly not surviving a hunt, and they both end up being okay but it was a close call, which leads to Cas getting emotional and truly crying in front of Dean for the very first time.
And Dean being heartbroken when he notices it because that is just not right, thus gently brushing Cas’ tears away, his thumbs tracing both Cas’ cheek bones as he softly says “Hey, Cas hey, I’m here… Please don’t cry, I’d rather see my sunshine without a side or rain. Just saying…”
Then Cas smiling a watery smile because of that sappy remark before Dean takes him into his arms with a relieved sigh, and holds him there until Cas stops shaking.
Yeah, imagine that.