Robert H Hensley, AKA Jericho Brown & Bob Henry I played the Valentino character in Man's Favorite Sport" with Cathy Brown. The silent screen spoof of two trains crashing together with the piano playing the silent movie theme, was a send up of the kissing scenes between, Hudson and Prentice. After kissing up Marsha's arm several times and her always saying "we must think of Reginal", she finally says the last time "because the movie's over.", which let me say to end the film, "Oh!". All tounge in cheek. Not to be taken seriously.

Stan Freberg created a parody of movie love scenes called "John and Marsha". The two lovers just keep saying each other's names (plus an occasional "Oh John" or "Oh Marsha") more and more passionately. This became something of a standard joke, so in the early 60s the reference would have meant something even to people who weren't aware it originated with Freberg. Someone pointed out that the modern equivalent is a scene involving two slackers carrying on a conversation consisting entirely of "Dude".
As I recall, J&M show up twice in
Man's Favorite Sport?
: once when someone is watching a love scene on TV, and later when John and Marsha interrupt their usual dialog to announce "The End". The latter bit never struck me as terribly funny, but I'll forgive this film anything (mostly due to the wonderful Paula Prentiss).

It's most likely an inside joke or a strange reference to something other film or tv-series.
"Losers always whine about their best. Winners go home and **** the prom queen."
-John Mason