Two People Laughing At Me Over Something Really Stupid? It’s Still Bugging Me?

I guess I just need to get it off my chest. I’m still in High School, and I’m pretty well-liked, I don’t dress weird, act weird, etc. I’m completely normal and have tons of friends. In English class today, I was reading out of the book, and there is a girl and a guy, best friends, laughing. They always laugh at everything. One time I remembered they laughed at the expressions of people as they watched a movie, and made fun of them to their face. Basically, they are so open about talking about people, embarassing them, laughing, etc. The one girl is known for TONS of drama. I think she feels life is boring without it? But the whole time in English class her and the one boy just sat there and laughed and giggled. They laugh and giggle annoyingly the whole time anyways everyday, but they kept glancing over at me. I kept looking over at them, and once the girl said between giggles, “What are you looking at? Can’t you see I’m trying to look out the window?” And resumed giggling. On my second to last period of the day, I was sitting with a friend in that class who has had huge trouble with the girl who was laughing at me before (they are from the same social group and all) and she said, “So, I heard Amanda was kind of rude to you today….She said you kept looking at her and she had to say ‘What are you looking at? Can’t you see I’m looking out of the window?’ and she thought it was just HALARIOUS apparently that you kept looking at her. I heard Dustin was doing it to, but I doubt he meant anything. He is like a big furry Kung Fu Panda!” I was both relieved that it wasn’t about my appearance, but nerved that people knew and I never told anyone. I mean, it bugs me, and I know the girl and guy are just being themselves, they do this every single day to litterally anyone and everyone, but still. It kind of hurts still that someone would have the nerve to sit there and giggle and laugh and whisper about me over litterally nothing at all. Help? Tips? Advice? Opinion? Thanks, I just feel like they should grow up.