moment of truth

So I've been dating this guy for 5 months now, yet my folks know him as a friend. We had been together for about 3 months when my mum met him as a friend. When we left lunch she said "He is nice person but keep him as a friend." But Ofcourse because my folks and I were separated by different cities I didn't care and continued seeing him. When I got home for vac, she continuously spoke about him for 5 days straight, told him to come visit and even arrange his accommodation. When my dad took him out for drinks, another drunk friend was teasing my dad saying that he is my boyfriend etc. my mum got annoyed because she said if I'm dating anyone I need to tell her. However I do feel that if I tell her she is going to be annoyed and try dictate my life. I'm 20 and he is 25. We work really well together. I feel like she is so contradicting and I have no idea how to go further and tell her I'm seeing him. Also we are a mixed racial couple so.. Please help with friendly advice..