I need help, does the "no age difference" matter?

i have been dating my boyfriend for almost 2 years, where he turned 19 in april and i will in december! i know it sounds weird, but we are madly in love, and i never felt that he is immature! can anyone tell me what are the drawbacks of this relationship on the long run, my parents did deny this relationship because of the age, so what do you think?