As difficult as it sounds to be dealing with this shift in how they see/treat you, the fact that they say things like "this is guy stuff" sounds like true acceptance based on what you've said about their view of women in general. As a kid, I remember always wanting to sit with the females at family dinners, my mom and aunts and female cousins having one conversation, while the males had another. It was never on purpose and not every time we got together, but the separation seemed somewhat natural.
I've also been reading posts of others on here that discuss the change in how their coworkers treat them. For some, chivalry has suddenly appeared in surprising ways. For others, the condescension and "mansplaining" has appeared. Even though you don't necessarily feel that all of your personality or interests have changed, just your being a woman has signaled this shift for your family.
I worked a chair massage gig for a company a few weeks ago. A guy was talking to one of his coworkers, saying that he'd signed up for "her" chair (meaning mine, as he pointed towards me). I got all flattered, but then he got on my chair and I got this kinda weird kinda creepy vibe. Something my female friends discuss a lot, but it was my first time even considering that. Becoming a woman is going to include these negative or uncomfortable elements, but that may just be something I need to expect in losing male privilege.
