Should a suitor be informed about a previous relationship, even if he hasn't asked about it?

If a servant sins and Allah conceals him, he must not expose himself. Rather, he should conceal it, repent, and feel remorse, and that is sufficient for him. There is no need to inform a suitor about a past sinful relationship, for the Prophet, peace and blessings be upon him, said: "Whoever is afflicted with any of these abominations should conceal it with the concealment of Allah, Exalted and Glorified be He, upon him."