Married Life Gets a Little Wilder Than Expected

So here's a bit of a story from my life that I've been ruminating on for the past few weeks. See, my wife and I have been married for about 25 years now. We've got two kids who are both out on their own these days, and we're kinda in that phase where we're trying to rediscover each other. It's not that we don't enjoy sex anymore; it's more like the spark is fading a bit with our usual routine. So I suggested something new: why not try being a little naughty together? She agreed enthusiastically at first, but things got... interesting. We started off slow, playing around with some basic toys and role-playing. It was fun and we both enjoyed it, but then she asked me to be her daddy one night. At first, I laughed it off as a joke, but when she kept asking for it seriously, I agreed. Here's the thing: in my head, it wasn't a big deal. We've been together this long, why shouldn't we explore something different? But then it happened. She wanted me to be her father figure, and she wanted me to take control like one would with a young adult who needs guidance. I became 'Dad' to her in the bedroom, giving orders and disciplining her for little things that would normally just be playful teasing. It was weird but hot at first. She'd wear a sundress like she's in high school, and act all shy and submissive. We were both 18+, of course, and this wasn't about the real dynamics of our relationship, it was adult role-play to spice things up. But I had this moment where I felt like I actually did become her dad instead of just playing a part. That's when she said something that threw me off: 'You're such a good father.' It struck a chord in my head, because being a father is a serious thing. Now, here's the kicker: I'm not sure if this role-play should have boundaries beyond us both being adults and fully consenting. We've been playing this for a few weeks now. Is it normal to feel like you're stepping over some kind of line when you're just trying to keep your relationship fresh? Or am I making too big a deal out of nothing? It's funny because if someone else did this, they'd probably be labeled as kinky and adventurous, but now that it involves me personally, it seems more complicated. What do you think, should we stick with role-play boundaries or is there something deeper going on here? I'm looking for any advice anyone has to offer.