This is a great, classic clip. I remember seeing it when I was a kid and almost fainting, it was definitely a major clip, and it took me years before I saw it again.
Anyhow, a guy gets a telegram giving him a big break in Hollywood. The blonde girlfriend takes the telegram and runs away from it (she's protesting she doesn't want to be left at home while he goes to Hollywood). He chases her, tackles her down.
Cut to close up on the two, her on her back looking at him, and he says, very calmly, "Now listen....listen to me.......if you don't give it to me, I'm going to tickle you...."
"Please Bob...."
"I going to tickle you!"
"You promised, Bob...."
"I'm going to tickle you if you don't give it to me.....one.....
"No, dont, Bob....."
"...two...."
(Panic rising in her voice) "Howard, help! HOWARD, HELP...."
".....THREE..." and he digs in ribs and she starts laughing hysterically.
As he's tickling her, he bellows out "Give it to me" as she screams and laughs, but it cuts to "Howard" watching the tickling as two nuns all of a sudden come in to the room (all the while, tickling and laughing going on). At one point, a far shot shows him tickling her while her legs kick all over the place and then they are "caught" by the two nuns.
For the remainder of the scene......which goes on for a while....the girl looks absolutely flustered and out of breath.
The tickling itself, as far as the laughter, may or may not be "movie tickling", acted laughter....but it doesn't matter, it's still a classic scene.....and basically one of my top scenes of all time before I discovered tickling videos and the internet!
Hope this helps, and hope you can make a clip of it, Bella!