Search Results: flirting while in a relationship

I was introduced to someone (they) that either has low self of esteem or is a narc. I believe the mutual friend knew this somehow because it slipped that they liked and wanted to be with the mutual first!! I was never interested in getting with anyone but the mutual would not stop hyping me up about potentially finding a partner before an event where they'd be there. They were very needy/touchy with me from the jump I feel for it, thought I'd take them under my wing but dating and gifts and ily's were pushed on me way to fast. Before that though the mutual, they, and I would be hanging out and the mutual would push they to get my number. Meanwhile there were times where the mutual would get annoyed that they would be texting too much and would tell me to tell they not to text or they'd be blocked. Either way I knew they still liked the mutual and the mutual would flirt back knowing we were 'dating'. Like make up your mind do you hate them or want to be with him. They and the mutual have hung out together while we were dating but certain events would slip out that seemed minor but they reacted as if they weren't supposed to say anything and would change the subject. Meanwhile the mutual would not text me to ask about they as much as other relationships, say what happened when hanging out, and wouldn't seem surprised or would seem dismissive over anything I brought up about they in person saying "they did that to me too". Either way I believe that they was bothering the mutual so much that the bone was throne to me so she could be left alone but once she saw the outward things they'd do for me the mutual became jealous or changed mind about throwing the bone and knows that the bone can easily be taken back because they like the mutual first. Both they and the mutual are gone from my life because I don't trust them. I just want to know if that sound right or similar to anybody

If you want please explain your opinion. (Why yes, or why no)

Okay, so allow me to begin:
My friend is in a relationship with a girl, we’ll call her ‘A’. ‘A’ just so happens to know a mutual person, and this mutual person was flirting with her a bit. ‘A’ also has more than one IG account that don’t seem to be in use, but she does appear online on those accounts once in a while. ‘A’ didn’t stop the mutual from flirting whatsoever and allowed it to happen. I only have very few dry DMs, but who knows if they took place from other accounts that something way worse than what I have saved.

‘A’ also appears to be a sugar baby and my friend has no clue. ‘A’ still follows this account on twitter. And she’s not on it often but seems to also visit other folk’s islands on ACNH. One of them being 15yo and ‘A’ being 22F. Nothing wrong with ACNH, but she does speak to a lot of strangers through social media and online games without my buddy’s knowledge. And I don’t believe that the minor nor ‘A’ are related in anyway.

Is this cheating? Or some sort of weird emotional affair? The heck am I supposed to do?