Higher stress levels are linked to more disagreements with lovers, an erotic deterrent of the highest level. In fact, in order to engage with another person on any intimate level we need to perceive enough safety. This safety helps us feel sexual arousal and bonding with our partner due to the release of the hormones oxytocin and vasopressin.
Helping an elderly parent with bathing, can come with some fear or embarrassment for both of you. You want to maintain the person's privacy, dignity and independence as much as possible. It might take longer than it used to for the person to do something for themselves, but the benefits far outweigh the extra time.
As a community nurse I've heard stories from families who, instead of checking items off shopping lists and going to holiday parties, were taking someone to multiple medical appointments. Or, they were worried and asking me how to keep their mom calm and comfortable at the busy family gathering as her dementia was taking hold.