Coming home with hickies

So back in May my boyfriend and I were just making out and stuff and he started to bite, kiss, and suck on my neck leaving a huge hickey. I was able to hide it from my parents that night with my jacket, but honestly I wasn't too worried about them seeing it anyways. I don't see anything wrong with hickies but my parents on the other hand think that teenagers doing anything sexual is just wrong. So the next morning my family and i went to Sam's club. I wore a long sleeve t-shirt that covered up my hickies just fine. But I had a bag on my shoulder that pulled my shirt down. That's how my mom found out and yelled at me in public. Then she told my dad and he yelled to. They then explained to my siblings what it was and how i got it? My mom's first response was "God dammit! Can you not be a slut for two fucking minutes?!" Then they just quit talking to me and wouldn't let me see him. I got to see him for a few hours before he left for the summer and my parents even yelled at me for laying my head on his chest while watching a movie together. He comes home in 9 days and we plan on hanging out that Saturday, but my parents won't let me. I'm trying to convince them to let me, but it's been rough. Any advice on what to say to them? They hate him now all because of this. We are teenagers. It's not uncommon for us to be doing this type of stuff. My older sister was sexually active and you didn't say a word to her. Ugh. This isn't fair😔