OK, so for now I'm not gonna use real names.. but this issue is seriously got me fucked up. I (30f)(,let's call me lily) was seeing this guy (let's call him Mark(35m,) ) and when I say seeing I mean I was sleeping with him and thought maybe there could be more. But when I asked Mark if he was interested in something more serious he said no. Fast forward . .. I've moved on and was dating someone else and we even lived together. Things hit a bad turn and I needed to stay with my mom for a while only to find out the night I move back that MY MOTHER(49f) IS NOW SLEEPING WITH MARK.... I Lost it. But everyone is acting like I'm crazy for being upset and saying because I moved on I shouldn't care? Am I wrong for being hurt and disgusted by this? I'm honestly so lost . I no longer live with my mother. But I think I might have to completely remove her from my life. I honestly xant even explain how I feel . AITAH For being so upset?

Edit : my mom knew I was with this guy as I was living with her and he would come to see me at the house when I lived there (she even helped me make him dinner once) I honestly just feel so betrayed by my mom... I can't even believe this is actually happening to me. It feels like I could be part of the cast of shamless 😭😭😭😭😭 I'm so ready to give up.