Consider the effect of these two possible responses from the second person: (#1) "I wasn't at the party last night"; and (#2) "Yeah, that was a great party; I didn't know you were into rave music." Response #1 negates the offer, de-rails the scene that the first person created, and even makes the first person look bad by belittling his or her offer. Response #2 accepts the offer, and builds on it (which affirms it even more), making both characters look good and solidifying the scene's direction for the audience.
This "yes, and" technique is very powerful in non-theatrical scenarios as well. A few months ago I saw a billboard for a local university. The slogan read: "Do well. But do good." The "no, but" model here makes me feel like doing well is a bad thing, but I can compensate for it by doing good. The billboard would be so much more effective if it read "Do well. And do good." The "yes, and" version makes both halves of the slogan positive and worthy of my pursuit.
Consider how this can play out in your work life. When a colleague proposes an idea (aka makes an offer) that you dislike, rather than jumping into a "no, but" reply, give the gift of "yes, and" -- take a moment to consider how you can accept the offer and even expand on it in a way that makes you both look good.