If she gets jealous when you talk about your time with your boyfriend or if she tries to undermine your relationship in some way. For example, she might say things like 'He doesn't seem that into you' or 'You two are so different, it won't last'. These are all red flags that she might have an ulterior motive regarding your boyfriend.
Well, first of all, communication is key. If you suspect something between your best friend and your boyfriend, have an honest talk with both of them. Maybe it's just a misunderstanding. For example, I once thought my best friend and my boyfriend were getting too close because they always texted. But when I talked to them, I found out they were just discussing a surprise for me.
One sign could be if your best friend is overly secretive around your partner. For example, they might always have private conversations that seem a bit too hush - hush. Another sign is if your partner suddenly starts acting differently towards you, like being more distant or cold, and at the same time seems to be getting closer to your best friend. Maybe they start having inside jokes that you're not a part of. Also, if your best friend always seems to be around when you're not there, like they're waiting for you to leave so they can be with your partner, that could be a red flag.
First, communicate your feelings to your best friend. Let her know that it makes you uncomfortable. For example, say something like 'I'm not okay with you still being friends with my ex'. Second, set boundaries. Maybe ask her not to talk about your ex in front of you. I did this with my best friend, and it worked out okay in the end. Third, try to focus on your own life and new relationships. Don't let this situation consume you.
One sign could be if they start to keep secrets from you. Best friends usually share everything. Another is if they suddenly become very competitive with you in a negative way, like trying to outdo you all the time.
These kinds of stories often involve complex ethical issues. In most cases, having a sexual relationship with your best friend's boyfriend is clearly unethical. It betrays the trust of your friend and can cause great harm to the friendship. However, in some fictional stories where there are special circumstances like the best friend was already in a bad relationship and had given some form of consent, it still makes for a morally gray area.
In my toxic best friend stories, a sign was her being two - faced. She would act nice to me when we were alone but then be mean or talk badly about me when I wasn't around. Another sign was her lack of support. When I had goals or dreams, she would either mock them or not encourage me at all. And also, she would always try to compete with me in a negative way, like trying to outdo me in everything instead of being happy for my achievements.
One of the main consequences is the loss of your best friend. No one would be okay with their friend having sex with their partner. Your friendship will likely be broken. Also, it can create a lot of drama in your social circle. People will take sides, and there will be a lot of gossip.
If your best friend steals your boyfriend, it's a really tough situation. First, I would cut off contact with both of them. It's a betrayal from two people you trusted. You don't need that kind of drama in your life. Then, focus on yourself. Go out with other friends, pick up a new hobby, or just do things that make you happy. Don't let them see you broken.
My best friend's boyfriend was an artist. He often painted portraits of her. Once, for her birthday, he organized an exhibition in a small local gallery with all the paintings he had made of her. It was a really sweet gesture. Many people came to see the exhibition and my best friend was over the moon. This not only showed his love for her but also made her feel special in the eyes of the public.
One story is that they were best friends since childhood. They knew everything about each other. One day, the guy realized he couldn't imagine his life without her. So he took her to their favorite park and just blurted out his feelings. She was surprised but happy as she had been secretly in love too.