Is AUTHOR wrong in the post ? POST : I admit title does make me sound like the asshole. The 3 of us have been friends for years. A year ago my friend (I’ll call her Sally) got a boyfriend. She’s gone AWOL since then, we’ve met up about 5 times over the last year which is very different to how often we used to see each other. On a frequent basis she said she was too busy to meet up but then got upset when me and 3rd friend (I’ll call her Tina) met up without her. 
Over the last few months I’ve messaged suggesting things to do a few times and she’s not responded. Correction, she responded to other parts of the message but ignored the bits about meeting up. I admit I got fed up and have been feeling lonely recently and stressed with work so I privately messaged Tina and asked if she wanted to go to dinner. We went and had a lovely time. Tina and Sally were talking about something when Tina mentioned meeting me. Sally has gone off on one saying we’re having secret meetings without her and then messaged me asking why am I purposefully excluding her.  
She’s now turned around saying she already feels isolated and she thought we’d stick by her as she starts a family (Sally is not pregnant), and force her to hang round with us not just abandon her and meet up without her.
My opinion is friendship is a 2 way street, she says she feels isolated but ignores messages and isn’t available to meet. I didn’t think I’d ever have to ‘force’ (her own words) a friend to hang out.