Pulling a "Jack Tripper" describes a situation/conversation whereas 2 or more parties are talking - or overhearing - different subjects, but don't realize it. The misunderstanding is usually rife with sexual innuendo. This type of comedy exchange was used extensively in the 80's sitcom "Three's Company", hence the name.
Jack Tripper: Mr. Furley is standing outside the bathroom and eavesdropping while Jack and Chrissy are installing a shower curtain Okay, Chrissy, I'll get in the tub with you, then we can get it on.
Chrissy: Get next to me, I'll show you what to do.
Jack Tripper: This isn't exactly the first time I've ever done this.
Chrissy: Maybe so, but girls are better at this than boys.
Jack Tripper: Come on, Chrissy. A little less talk and a little more action, okay?
Chrissy: Okay, you do your part and I'll do mine. I don't think it'll reach!
Jack Tripper: Of course not, you've got to unfold it first!