I love most of my in-laws. They’ve been nothing but kind, inclusive, and helpful when we need it.
FMIL is a different story. I really did try when I first moved up here, and she didn’t seem so bad. Well, turns out she was just pretty good at hiding her crazy. I’d find out later that some of her stories weren’t true (e.g. she’d tell it as though she acted calm and collected, but we’d later find out that she got drunk and had a vitrolic alcoholic meltdown spanning several hours). We luckily don’t get much of that anymore (once she had a total red-faced spitting & screaming meltdown because we asked that she not give our pets treats for a few days; she threatened to call the police), because she doesn’t visit drunk, but we do get VMails occasionally.
She also likes to grossly overstep her boundaries, but FI and I are so much better about keeping that in check. A few years ago, she had taken it upon herself to reorganize our entire kitchen while we were getting ready. I had a potted plant outside the door, and opened the door one day to find her standing there with the pot, sans my plant, with her “prettier flowers” inside of it instead. At one point, she was obsessed with having my cat and kept trying to bargain for him. He’s MY cat and I love him!
Then there are the inappropriate questions or comments. One would be the time she claimed that this was HER wedding (even though I am doing all of the planning, and FI and I are the only ones paying for it). Another was when she called here and asked if I knew who my real father was. WTF? Even if my father wasn’t my biological dad (which he most certainly is), he is the one who loved me, raised me, and taught me what life is! YES, I know who my real father is.
Luckily, FI is on the same page with me, and puts up with even less than I do. We deal with her by setting strict boundaries for ourselves, and enforcing them. I mean, we didn’t give her a set of rules or anything, but we’ve decided what we’re okay with and enforce those boundaries as they come up. If she doesn’t call before coming over, even though we’ve asked her to so many times, we don’t answer the door. If she starts being rude about something, FI promptly reminds her how rude she’s being and hangs up the phone if necessary. She isn’t allowed to call him screaming about something, like she does to other people; he’ll hang up and won’t engage in an argument. We don’t tell her many things anymore, not really more than you would tell an aquaintence, because we know she’ll sit and obsess about it.
As for how I personally deal with the frustration, well, this is one way. It’s nice to talk to some other people about being in similar situations. I also arrange to be busy if I know she’s coming over, whether that’s an impromptu shopping trip, a nice long shower, or conveniently leaving early for work. On my phone, I’ve set her number to go straight to voicemail, so I never again have to deal with her habit of burst calling interrupting my business. So I mainly work on minimizing my time with her as much as possible, and support FI in upholding boundaries. It seems to work pretty well.