Does seeing madhy after a phone call with a female relative, who was previously seen naked, and which included sexual talk, invalidate the speaker's fast, and what should he do, and should his friend abandon him?

A fasting person must avoid everything that arouses his desires, and his limbs must abstain from what is unlawful. The emission of pre-seminal fluid (madhy) due to talking does not invalidate the fast. However, talking about sex is forbidden and is considered the adultery of the tongue. The perpetrator of such an act must be advised and reminded of the evil consequences of his action, and that recompense is according to the nature of the deed. It is permissible to either shun him or maintain contact with him through advice, depending on what serves the best interest.