Why Am I Into This?

So here's my situation... I'm in my 30s now, a nurse at the local hospital. Married for about ten years to a lovely woman who adores me and our three children, all under the age of eight. We have a stable home life, but lately, I've been drawn into something that seems completely out of character... DDLG stuff. Daddy play, you know what I mean? It started when an online friend suggested it as a roleplay scenario for fun chat rooms. The idea appealed to me more than I'd expect, I guess there's something comforting in the power dynamic, maybe because my job requires a bit of authority?... But I've found myself fantasizing about it more and more outside of these chats... It feels odd, though. Not just because of societal norms and whatnot... but because I feel this overwhelming need to take care of someone else, to be the one making all the decisions, even in a non-physical sense. Like when my partner looks to me for advice on everything from car repairs to whether we should send the kids to private school... But these fantasies, they're not about her or our family... It's like an escape into another persona, Daddy, that doesn't exist outside of those chats and stories I write alone. And honestly? The more I indulge in this fantasy world, the less connected I feel with reality... So here's my question: am I being selfish by having these fantasies while I have a family that needs me? Is there something unhealthy about wanting to be someone else when I already have such a supportive partner and children who look up to me as their father figure? Anyone got thoughts on this...?