Merging families can be really hard, and I imagine it’s just as awkward for them too. Building relationships just takes time and will progress naturally. One of the things I suggest to my clients when they’re building relationships is to find one thing in common and one thing you really appreciate about the other person.
Focusing on the good will always beat focusing on the bad (or weird), and it will project in how you interact with them.
It could be small to start but you don’t want to force it anyways, which it sounds like you might be doing. For example, my best friend’s mother-in-law is super stylish. Even though she can be a little overbearing, you gotta hand it to her that she always looks great. And that’s a point that they can connect on.
Maybe one of your in-laws is a great cook or a great story teller. Start to look for and explore the positives that you can find in others and just make mental notes. Focusing on the good will always beat focusing on the bad (or weird), and it will project in how you interact with them.
As far as spending time with them, I don’t think you’re alone in this boat. Just like I’m sure being at work can be a drag sometimes too, spending time with in-laws is a necessary evil. If it’s just about getting face time in, try and organize something that you can you can invite others to as well so there isn’t as much pressure to keep them entertained. Think: a game night or day trip to the lake.
But if it’s something more mandatory like the holidays then you may have to just grin and bear it. Focus on the positives. Your financé will appreciate you for it. On that note, remember these feelings when it’s time to hang with your family too, as your financé will probably have similar feelings.