Knowing what phase of the cycle you're in and what your body's unique needs are at that time of month is key to a healthy relationship with your body. (floliving.com)
On a basic level it is appreciation for the little things we do for one another which shows we care (i.e. Gottman), which needs to be reciprocated with a sense of appreciation (see Lyuborski — on gratefulenss as key to healthy relationships) (positivepsychologynews.com)