Don't respect my partner's partner
Newbie here! (and relatively new to poly too...just a couple years)
So, I need a bit of guidance in my relationship. I'm one of the ends of a poly V (pretty much) and I am totally in love with my partner and he's awesome. His other partner, however, is someone I have some problems with. It's been three years, and we've made it work thus far but circumstances are changing and we need it to get to a point where she and I more than just tolerate each other. We will be much more present in each others lives, so I really want to try to make it better.
The problem is that I have absolutely no respect for her. She lies...a lot. To be fair, I don't think she does it maliciously - she exaggerates things in her head, or lies out of insecurity or fear, or whatever. But every time I talk to her, I find out later that something she said was a lie. To me, that is a huge deal, and after this long, I just really don't respect her at all. She's a nice person and everything, but I don't trust her as far as I could throw her.
The thing is, I don't know what to do about it. My partner really wants us to get along, but when I bring up that I don't trust her, he just says to not really take anything she says as truth until I talk to him about it. But I can't do that...I can't try to learn to respect someone while trying to train myself to take everything they say with a grain of salt.
Anyway, I would really love some advice on how other people have grown to respect their partner's partner. Did it come naturally, or did you have to actively work at it? If so, what did you do? Did you ever have to deal with someone who isn't often truthful? If so, how did you handle that?
Thanks in advance for any and all advice!!! Can't wait to meet and chat with people on here!