When Venus joins Mars, love’s two faces — affection and desire — trigger each other. The result is an ardent urge to connect energetically with another person. That linking can take many forms: the passionate merging of uninhibited sexual expression, the physical exuberance of sports, the verbal roller coaster of honest, constructive disagreement, or the senseless emotional bloodshed of a silly fight. This is how Steven Forrest puts it.
progressed planets/charts are more ‘internal’ changes, evolvements rather than ‘events or external’ matters. I don’t read prog charts as stand alones it’s more important to see where these planets are moving in the natal chart Your natal chart is like a photograph as unique as your fingerprint, BUT the 10planets in the sky have not stayed where they were in your natal chart, they have all moved. Predictive astrology is mostly maths where those 10planets are now and the mathematical aspects they make to your natal charts ie: 180'=opposition, 90'=square, 60'=sextile and 120'=trine.
So your personality, grows, develops, changes, matures as we get older, this is reflected by your sun sign changing from it’s natal position to the next sign along, so does your Asc and MC sign change. In fact from sun to mars especially are important, as the outer planets really don’t move much, using a ‘day for a year’ secondary progressions.
“Progressed Venus square or opposition Mars You may not always feel that your efforts are getting you what you want, but that may be more the result of your changing tastes than of your ability to serve them. Determine your desires and don’t move the goal posts before you can get your kick in the air — then it will sail smack between the uprights.” http://www.cafeastrology.com/progressedplanetsaspects.html