The lack of give and take when the square predominates can be very wearing. Wherever you have a square you have a potential issue that has to be integrated into the framework of the life of the relationship so that it becomes an active part of the whole. Positively this can create a great dynamic with potential for motivation and acceptance of the other's qualities, but if there are too many, it becomes burdensome. If you've ever watched a bricklayer building a house, he fills his hod with only as many bricks as he can comfortably carry. That way he is productive and the building grow.
Squares are like bricks.
They build walls but also create safe boundaries. Relationships need a few brick walls to climb in order to test the validity of the relationship. It's often through a certain level of healthy stress that we can achieve and there is potential for achievement with a good balance of squares. It's the same with a Trine flavoured relationship. It can be very bland.