In Vedic Astrology, the fifth house from the ascendant is the house of love, the sixth house shows fights, arguments etc, the eighth house is the house of loss, sex, and the 12th house is bed comfort, loss.
When there is a connection between the 5th house with any of 4th, 6th, 8th and 12th house; or if the lord of the 5th house is in these three houses or connected through these three house by nakshatra then it shows loss in love, break up etc.
While the 6th, 8th and 12th house shows the loss, the 11th house shows profit, fulfilment of desire; when there is a connection between the 5th house and any of the 6th, 8th and 12th house as well as the 11th house, in that case after break up the person can come back in your life.
Three planets - North node (Rahu), South node (Ketu) and Saturn are responsible for break up - or divorce, if the 5th housr lord is connected to Saturn and the nodes it indicates a break up like situations, in a male chart when Venus is connected with these planet and in a female chart when Mars is connected to these planets it also indicates a break-up or divorce, but if Jupiter is also connected or aspect the 5th lord, 5th house or Mars and Venus it indicates reconciliation.
Time of break up:
There is a concept of Dasha system in Vedic Astrology, during the maha dasha, antar dasha and pratyantar dasha if the 5th house, 6th, 8th, or 12th house gets connected during that period break up may happen.
Another interesting thing in both eastern and western astrology is Transit, when the nodes or saturn transits into the 5th house, or the nodes touches Mercury, Venus or Mars during those times break ups may happen.