As long as you drink less than 3 cups of coffee per day, there is no relation between coffee and breast size.
This myth about coffee and breast size spread due to a study which indicated that 3+ cups of coffee a day was associated with smaller breast sizes, but this study is surrounded with lots of criticisms like in the way of calculating the breast size. There are no other evidences or research done to back this claim.
Conclusion - You can enjoy at least 3 cups of joe with no risks of shrinking breast sizes.
Which coffee is best for weight loss?
How coffee can get you rid of puffy eyes?
Can coffee give you a blood pressure surge?
Why can't I drink coffee before donating blood?
How much coffee is healthy to drink daily?
How to make coffee masks for puffy eyes and dark circles?
Where can I buy coffee lover's merchandise like coffee themed t shirts, mugs?
How can coffee ground be used as a fertilizer?
Does coffee help protect skin from sun damage?
Which are the top 23 amazing coffee cultures?