What is the ruling on marrying a woman who refuses intercourse in the front passage but requests it in the back passage, and is it permissible to maintain a silent phone relationship with a former fiancée while being married?

You must fear Allah and avoid having ill thoughts about Him, for that is a characteristic of polytheists and hypocrites, and it is one of the major sins of the heart. No one has a right to demand anything from Allah except what He bestows out of His grace.

Ibn al-Qayyim said: "Whoever thinks that Allah punishes His servant and deprives him without a fault, or that He disappoints one who trusts in Him, has thought ill of Him."

Whatever calamity befalls you is because of what your hands have earned, so you must repent and seek forgiveness.

A wife's refusal to engage in sexual intercourse is unlawful, based on the saying of the Prophet (peace be upon him): "If a man calls his wife to his bed and she refuses to come to him, and he spends the night angry with her, the angels curse her until morning." Anal intercourse is not permissible.

You should advise your wife and remind her of Allah. If she does not respond, then take the matter to the judiciary.

As for your former fiancée, she is a stranger to you, and the relationship between you two must be severed.