I don’t understand your point?
Tell it to the Marines ???Basically I was saying.... ya right
When you do not quite believe/agree with something someone was saying...Tell it to the Marines is kind of a fun loving way to say...hey I do not buy what you are selling, that`s how I meant it, no malice intended.
The conversation between you and unkus back and forth I thought called for it.
Cary Grant used the expression in a very good movie...He needed to fool the Germans while doing a propaganda radio program...he was able to say ...Tell it to the Marines during the broadcast, it went over the German censors heads, and it told the folks back home what he was saying was not true.
The expression goes back to the Royal Marines... Google the phrase if you are interested, quite a rich history to the phrase...more than you wanted to know..
To me it simply means...ya right fun loving sarc