When you are dancing with a partner, it is important to remember, and be considerate of, your partner. In particular, consider what your partner can do, and what they show they want to do. A gentleman who tries to lead his partner into steps too advanced for her (or, dare we say it, for him), will not make the partnership look good, and will probably make his partner uncomfortable. A lady who starts to improvise extensively in a West Coast Swing while her partner just keeps time waiting for her to finish is probably not making a fan. A gentleman who goes into extended salsa shines while his partner dances a basic, waiting for him to pick her up again, shows a marked lack of awareness or consideration. Partner dancing is about two people dancing together, and in these examples, the connection is missing.
Do what you both can do as well as you can. If you and your partner are both capable of showing off, and want to do so, go for it. Otherwise, be nice, make your partner happy.