I want the lifestyle. My wife doesn't. We're trying a "she stays home, I go alone" arrangement and I don't know if it's working

She made pancakes for the kids while I stood in the kitchen door Saturday morning, just back from a Manchester club, and I felt a gap between us I hadn't felt before. That's the moment I knew the arrangement might not be working. The arrangement: once a month, I go alone, a Friday night, club in Manchester, do whatever I want with whoever wants to, come home Saturday morning. She doesn't ask for details. I volunteer only what I want. STI test every three months, condoms, no overnight stays outside that one night. We landed there after about a year of conversations, after I admitted I'd been thinking about the lifestyle seriously since before we got married. She was kind about it. Said she wasn't interested in any version for herself. Not soft swap, not voyeur, not even watching. Vanilla, full stop, in a clearly self-aware "I know who I am" way I respect. Three months in. Four Friday nights. First two were genuinely amazing. Third was meh. Fourth was last weekend and I came home weirdly empty. From outside maybe it looks clever. From inside I feel like I'm slowly draining something out of the marriage we used to share. We're 42 and 40, two kids, mortgage, suburb outside Manchester, the full picture. Anyone done this exact setup? Did it stabilise or did one of you eventually break it?