Stretch mark on breast is due to your post delivery status , and I can understand breastfeeding twin baby is also the reason , but the problem is , if correct medicine / oil is not applied on time to prevent it stop it .This stretch marks will remain for ever , which can be a cosmetic problem in future .
Next Steps
I understood your concern and noted the problem as well .I need to ask few more details to make a diagnosis and start treatment and advice which suits you. Pl consult me on Practo , so that I can help you better.book a time slot as per your convenience for consultation.