The Sun is the source of all energies. These energies stimulate the activities of the houses occupied by the transiting Sun and reinforce or weaken the planetary effects, depending on the Sun's aspect to the natal planet. When the Sun transits an inner planet, it may trigger a dormant aspect between that inner planet and a slower moving outer planet. If a planet is being transited by another planet when it is being transited by the Sun, the effect of the transit is strengthened.
Sun Inconjunct Jupiter
A Sun inconjunct Jupiter remind you that if it looks too good to be true it usually leads to inflated expectations and promises, high hopes or romantic dreams which never quite get off the ground. Things seem to start favorably but somehow slip because one or both partners indulge in irresponsibility or a lapse of good judgment. When the Sun person is Inconjunct the Jupiter person you'll need the luck as Jupiter seems to have forgotten how to give when you dare to gamble on what looks like a sure thing.