Respuesta :
The first paragraph contains the set of words suggesting a woman's inconstant love:
There is no woman's sides
Can bide the beating of so strong a passion
As love doth give my heart; no woman's heart
So big, to hold so much; they lack retention.
This claim is specially evidenced in the fourth line, as it implies the object is incapable of holding too much of something - which is in this case, it is romantic interest in someone. Therefore, this lack of retention may be interpreted as inconsistency.