Everyone likes my boyfriend except for my parents?

So my boyfriend and I are both 17 but we've been together for about 3 years now. He's everything I could've asked for and more, and I love him dearly. Over the years he's gradually been introduced to a whole bunch of my friends, and they all think he's cute and funny and they really like him, they always tell me I did a good job. My boyfriend is a little shy around my parents and since I don't see him often (every 2/3 months for 2 or so days) we spend most of our time in my room cuddling and watching movies and just enjoying eachothers company. My parents don't hate him but my dad always tells me it leaves a bad impression that he always wants to hang out in my room. That kinda makes me mad because we don't see eachother often so we kind of just want to chill but my parents are still kind of against him and I really don't know what to do about it. Any advice? Is this a bad thing?