TL;DR; I want to unfriend a coworker for her overly attached behavior, but she is also a QA of some of the projects that I develop.
I was dragged into a group of 4 girls at work without me trying to achieve that. We started going for lunch together and even hang out after work from time to time. At the beginning everything was great, but after we became closer, two of them started to act really obsessive, bossy and dramatic.
If I refuse to go for lunch with them or hang out after work, they get angry and start dramatic fights on skype, asking for reasons why I won't go eat with them. I have to explain myself all the time. Sometimes I just want to eat alone, reading my book or hang out with other coworkers (as I used to do). They do not understand this and do not accept it as excuse.
For example this is what has happened in the last 10 days:
Monday - They arranged party at home. I said I can't go because my sister came to town. They got mad and I lost one work hour to chat, explain myself and trying to please them.
Tuesday - We got into a really big fight, because I wanted to eat with other friends. We lost about 2 hours at work to chat.
Thursday - They were throwing a birthday party on Saturday and I turned down the invitation, because I was invited to a wedding months ago. I told them right away, not in the last moment, but still they acted like I did something bad (cold looks and silence for days).
Monday again - They arranged another home party for Thursday. I didn't want to go since this was my only free night of the week. I wanted to just stay at home. It wasn't a valid reason and after I turned them down 2 times in a row I felt like I had to accept.
This was too much for me. I can't concentrate on work and I have pressure even after work.
I can't ignore them in chat, because they are coming to my desk to talk directly.
I tried to explain to them that we are grown ups and have to understand each other for everyone has a personal life. Also that I'm not a very social person and I need my time alone from time to time. They genuinely don't get that.
THE MAIN PROBLEM: I work directly with one of these drama queens. She tests one of the interfaces I develop and we have official communication where other people are also involved. In the past, she already made some sassy comments about my tasks, but nothing too problematic. I don't want things to get out of hand if I directly unfriend her. Also the other two girls are pretty cool, funny and valuable for me. I don't want to lose connection with them. They agree with me that the others are too dramatic and don't like it either, but somehow they manage and don't see it as such big problem as me.
We have HR but I don't think this is case for them. From my eyes, these are "kindergarten problems".
I want to silently leave the group, but I don't know how.