I would suggest to express to any of your parents to whom you are bit friendly and to your brother or sister, who are elder to you, as you are 27, so you would have at least 2-3 years time to convince your parents and get married to your guy. Also your parents would enough time to know your boyfriend, as well as they would get time to plan and digest things through passage of time and eventually they would understand.
Important things to note while disclosing
Be strong and stay to your decision.
Prepare your self to face the unexpected behaviour from your parents
They may try to throw out your cellphone or may restrict yourself to step away from your home.
Discuss with your boyfriend that you are going to talk to your parents and their expected behaviour and post discussion consequences and a shorter period of distance in case things don’t go in right direction.
The most important thing in this scenario would be to trust each other and stay strong and love each other even though you both are not connected for few time.
Don’t expect that thing will go right in just few says or months- as you might’ve taken years to judge your future partner before thinking of him as life partner and he must have gone through many tests, so give equal time to your parents. Take care of your parents when they are disturbed and are in need. don’t react if they don’t agree, respect their decisions and ask them to take time and reconsider.