Does infidelity end a relationship? There is no simple answer to this question. Every person has a personal deal breaker in their relationship. For some it may be infidelity, for others not so much.
Only you can decide to either end or attempt to repair the marriage/relationship. There have been several very public cases of infidelity in which the decision was made to remain in the relationship. The reasons vary from love to maintaining the relationship for the sake of the family. No matter what you decide, make sure it’s your decision and not that of other’s around you.
Family and friends may be well meaning but remember they do not share a life and or a family with the unfaithful individual. You do. You have a vested interest in the outcome. Make the decision to stay or leave based on what you feel in your heart and mind, not family and friends. Listen to advice from others, but make the best decision for you and your family. If you decide to remain in the relationship I would recommend marriage counseling so that the two of you can determine what caused the breakdown in the relationship so as to avoid a repeat of the behavior in the future. Best of luck to you.