How do I get my mother to trust me more?

My mother and father do not allow my male friends (not boyfriend) in my bedroom with the room open while people over, I found out the other night when my father yelled at me with my male friend over in my bedroom (he was at my house for the first time and I was showing him things in my room, artwork and poetry and knickknacks and just things that kind of shine light into my past and my hobbies and such) and it was so embarring. It made me feel bad that my parents could not trust me not to do something with a male that I am not even that well acquainted with... because I am not in the slightest a promiscuous or slutty girl, I am quite shy and reserved and I really pride myself in having morals and things. My last (and only) boyfriend I dated for a year and a half and did not have with him (quite a feat these days). I am 16 years old and I have not nor ever plan on doing any drugs or drinking. I enjoy my life without those things, unlike many of my counterparts