Show Don't Tell Revisited
We all know the adage that in film writing we should show things, rather than telling the audience about them. Well, this relates to that concept but in a slightly different way.
Often I'll read a scene in which a man and woman meet for the first time and trade a bit of banter. Then the action description tells us that "there is obvious chemistry here" or something of that ilk. Similarly, I might read a scene with some gags in it and then be told "it is very funny" or "everyone finds this hilarious."
If two people are supposed to be clicking, your dialogue should be strong enough to convey that. And if it isn't, and is more subtle, then there are other actions you can write to more professionally convey your point. How about, "She catches his eye while casually brushing her hand against his arm?" That should do the trick, no? Same thing with comedy. If your dialogue, or description of the gag doesn't make the reader laugh, you simply have not done your job. It probably isn't really that funny, and telling us it is won't make it work on screen.
There is one other reason why writers might do this sort of thing, and if this applies to you, than recognize it and just cut it out. Sometimes, the writer may have actually done his job and conveyed the proper tone, but still writes something like this. That indicates a lack of trust, both in one's own skills as a writer, and in the reader or audience. Learn to trust and respect your readers and viewers. Don't talk down to them.
And more importantly, gain confidence in your own skills!