Cons are very lucrative and many of them go by a script. So yeah, a lot of public J/M interaction is for show. And work-related. Now Jensen saying Destiel doesn't exist is absolutely true. He meant that lol. But he still has a job to do and conventions are part of that. Unfortunately, throwing an occasional bone to insane people to keep them from lashing out via death threats and homophobia accusations (that almost messed up his image) is part of that job.
When he showed him his underwear he was in the middle of a breakdown after seeing hellers accusing him for months and months after he said destiel does not exist during a con. Then after this, they got trending, let’s show JA some love!! Fuck psychopaths. Messed his head up to the point of having a breakdown.
Ah yes, the jackles breakdown.