Your family makes me want to see other people...
So, I don't even know where to begin. I keep seeing a similar scenario play out on reality tv involving family members creating friction in relationships. As cliche as it may seem, it has been or is a reality for everyone at some point. The real question is if you're willing to allow your family or your significant other's family get in the way of your happily ever after.
Now, the answer to that seems easy enough, but it really depends on the level of disrespect from the mamasistercousinaunt (because it's usually one or all of them). More often than not, it's the mom making the situation difficult because they are too attached to their child. Monday, I watched the drama unfold on Love & Hip Hop Hollywood. Lyrica Anderson's mom (Lyrica Garrett) keeps meddling in her daughter's relationship. It was to the point where Lyrica Anderson eloped with her fiance to avoid drama between her mom and his. This only added fuel to the fire. As the season continues, Lyrica's mom is starting to look more and more like a "misery loves company" type. She's single and doesn't believe that her daughter's husband is good enough. It seems to always be like that. The mom is always single and lonely and basically feels like she's losing her companion by letting their child go. Unfortunately NO ONE will be worthy of them letting go because apparently NO ONE is worthy of being in their lives.
Here's the thing. If you feel that your companion IS good enough for you, you HAVE to check your mom/family member for the sake of your relationship. I'm not saying be disrespectful, but you have to let them know that their antics and/or opinions have no place in your relationship. This is reassurance and validation to your significant other that you're invested and their feelings are valid. It also wouldn't hurt to try and find a distraction for meddling mommy.
Otherwise, you'll be single and lonely just like mommy dearest.