Britney and Jamie Spears possibly reconciling is something Sam Asghari certainly has an opinion about, but getting him to share it ... well, that's another story, especially when the guy's got Christmas on the mind.

We got Britney's ex-husband out Wednesday in L.A., on the heels of our report about Brit warming to the idea of burying the hatchet with her old man after his recent leg amputation.

Keep in mind, Sam's the guy who once called Jamie a "d***" ... so, of course, we wanted to get his opinion on the potential father and child reunion.

Check out the interaction, for yourself -- Sam was happy to send season's greetings to the Spears fam, but beyond that ... well, you'll have to read his face.

He refused to answer questions about his ex-wife and ex-father-in-law ... and trust us, we tried every angle, including bringing up Britney and Lynne reuniting last week.

His shutdown might be a sign he's done talking about BS and her family drama, but more likely ... he and his ex have agreed not to speak about each other in public.

Remember, Brit and Sam filed for divorce earlier this year -- and late last month, we learned they were close to a settlement. So, it makes sense he's not looking to sink any ships with loose lips.