It is a widely known fact that men are attracted to breasts on a biological level.
According to research, a full cleavage is an indication of good health and fertility, which is what triggers a man’s instinctual attraction towards breasts.
Additionally, playing with breasts during sex can stimulate maternal bonding, which is satisfying for both partners.
Some evolutionary biologists have even suggested that full breasts store needed fat, which also signals good health to potential mates.

Breasts are also a symbol of sexuality for many men, and cleavage opens the door to exploring that aspect of femininity.
Overall, there may be several reasons why men are drawn to breasts, but it is a natural and instinctual desire deeply embedded in their genetic makeup.