My (22 M) best friend (23 F) has been acting very cold and actually ignoring me for a few days. We are also coworkers at a retail store, so obviously even outside of conversation it is very evident that the vibe is off, even other coworkers have commented on that fact. This all started when I met her little sister (21 F) a couple months ago. I thought her sister was cool, and after this hang out my best friend brought it to my attention that her younger sister found me very attractive. at the time I was talking to someone romantically, and didn’t entertain the thought of ever pursuing her in this way. My best friend is a bit persistent, telling me that my sister and her would make for such a good match, but every time she mentioned it i would brush it off.

Flash forward to a few months later, the person i was talking to romantically told me that she wasn’t looking for any long term commitment, so we stop talking. My best friends younger sister and i talk from time to time, usually brief conversations about football or video games. after one of these conversations, i head to work and my best friend calls me a creep and tells me to stop talking to her little sister. she explains that she is nervous that i’ll develop feelings for her, and that i’ll eventually have sx with her. she doesn’t explain to me why either of these things are bad or something to be avoided, she is just insistent that they will happen if i continue talking to her. in fact, she makes me swear on my terminally ill mothers life that i will never have sx with her sister. she insists that i stop talking to her, and i do.

within the next few days, her sister comes into the store and starts browsing around, and i ignore her. i don’t start conversation, i don’t say hi, i just completely ignore her. after her sister leaves, my best friend comes to me, upset. she said that by ignoring her i’m making everything awkward, and says that she wants us to be friends. at this point i’m very confused because of all of the mixed messages, but once again i listen to her, and i keep having these little conversations with her sister. over the course of a few days, these conversations are getting longer and more in depth, but none of them are romantic or flirtatious, we are just getting to know each other more.

the next time that i worked with my best friend, she completely ignored me for the entire shift, and hasn’t been answering any of my calls or texts, every time i ask her to hang out she blows me off, and flakes on me for pre established plans as well. i have a feeling that she is upset with me, but i don’t understand why.

When i have tried to reach out to her to talk about this situation, she blows me off, or when we’re at work she completely avoids the topic. if i am in the wrong, i would love to know why, but she hasn’t communicated to me that i am, and if so for what reasons. i feel like maybe i crossed a boundary at some point but this entire time ive only been going by the little information i do have. i would talk to her sister about this, but i don’t want to drive a wedge between them or make this entire situation into something more than it is. AITAH?