Food of which a man has eaten of is generally lawful for a woman

There is an issue I have been researching and questioning the scholar about for which I have not yet gotten a proper answer. Due to this my heart is not at ease. The issue is that within my in-laws, there is the notion that if a marriageable (غیر محرم) man or woman drinks or eats something from a container, then it is understood to be Haram for another marriageable man or woman to eat or drink of it (i.e. the food that the marriageable person has eaten from). There is no problem is a non-marriageable relative eats it, otherwise the food will just be wasted. If a marriageable person eats of such food, he or she will be blameworthy. What is the ruling on this as per Shari’ah? Please provide a detailed answer through the light of Quran and Sunnah.

الجوابُ حامِدا ًو مُصلیِّا ً

It should be understood that the food of which a man has eaten of is generally lawful for a woman who is marriageable to him. Similarly, the food of which a woman has eaten of is lawful for a man who is marriageable to her. However, this will be disliked if done with lustful inclinations towards that (marriageable) person. Though, there is no impurity in the food of which someone else has eaten.

مأخَذُ الفَتوی

کما فی در المختار : (فسؤر الآدمي مطلقا) و لو جنبا أو كافرا أو امرأة ، نعم يكره سؤرها للرجل كعكسه للاستلذاذ و استعمال ريق الغير ، و هو لا يجوز مجتبى .(۱/۲۲۲)۔
و کما فی الھندیۃ : و کراھۃ سؤر المرأۃ للأجنبی کسؤرہ لھا لیس لعدم طھارتہ ، بل للإستلذاذ کذا فی النھر الفائق الخ( ۱/ ۲۳)۔
و کما فی البحرائق : فقد صرح فی المجتبی من باب الحظر و الإباحۃ أنہ یکرہ سؤر المرأۃ للرجل و سؤرہ لھا الخ(۱/ ۱۲۶)۔