I think its just because she's a woman. Women don't generally require sex as much as men do. Men are usually practically dripping with Testosterone and all they can think about is sex. Its just the difference in how men and women are made. Nothing is wrong with neither one of you. However you might inquire with the lady if she is having any dryness issues because women do as they age and that can make frequent sex uncomfortable. Women get that way as they age as their hormone levels drop. A water-based lube might help. Also a lot of women get fibro as they get older and don't feel like having sex or doing anything else for that matter. Having to bath that old man may also be a turn off or he may be making advances towards her so she's tired of dealing with a man by the time she gets home. Just some thoughts...