That almost shy yet genuine smile Jensen does whenever he talks about Misha/thinks about Misha, usually looking down and not making any eye contact with people while doing so, even though Misha isn’t currently with him. It often goes together with blushes and a twinkle in his eyes, and sometimes with him fumbling with his clothes or whatever he’s holding in his hands.
If that didn’t help, this might:
Gifs not mine.
I hope this was helpful! :’)
Compare:
Jensen’s ‘Misha laugh’
An incurable affliction which presents acutely in one subject named Jensen Ross Ackles. Symptoms include a partial loss of body strength, invariably accompanied by raucous, explosive laughter, the angled tilting of the upper body, visibly weak knees, shortness of breath, and, occasionally, spinning around on the spot before leaning against a stable object in order to prevent total collapse. May be followed by watering eyes and an inability to look at anything except Dmitri Misha Collins.
From the case evidence reviewed here, I think I can safely rule that the subject, Jensen Ross Ackles, has no obvious aversion to this phenomenon, despite its massive effect on his physical and mental well-being. (Professional opinion is that I think he likes it.)