Can I date my sister's ex?

AGONY I RELATIONSHIPS

My sister dated this man for a good number for years. They even shared a house for two years. The relationship, however, did not make it to the alter. Neither did they have any children. Now the man and I have fallen in love, but I am worried about the complication the relationship will bring given his history with my sister. I do not want to miss out on love. I'm I being selfish.