Just a story time and I wanted thoughts

Ok hi so I (17) started dating this guy (19) about 3-4 months ago. When I met him, he and his ex had just recently broken up and she just so happens to go to my school and is the same age as me. Ever since September when school started, she gives me the most HORRIBLE dirty looks. Like atrociously bad. And then a month or so later my boyfriend was like “I have something uncomfortable to tell you” and I thought he had given me an STD or something but no, he told me that his EX had “accidentally” ordered a package to his house and that he had to drop it off at her house. He seemed genuinely annoyed about the situation but I got to thinking.. how in the HELL would she do that accidentally? She did live with him for a bit while they were together but last I checked, you need to confirm the address for Amazon packages… she also waited to tell him a day before it arrived. Isn’t that so stupid. I actually want to drag her ass like she pisses me off after that whole thing.