Pancreas. if the pancreas malfunctions, it could affect the GI system as well as metabolism. if it is not producing digestive enzymes such as lipase or bicarb, this could lead to problems digesting food. if it is producing odd levels of insulin or glucagon, this would affect the systems that those hormones interact with, leading to excess blood glucose or too much glucose being taken up into cells
Well, this is to be because if you have a long term relationship, that right there says that you are happy with your partner. Furthermore, as you are in your late adulthood, you tend to get bored and not wanting to have anything to do with that. Hope you find this helpful!