What's the longest you had a consistent FWBs?

Curious because I've currently been in a FWBs relationship (32M, 30F) for like 10 months. We started as dating but realized it probably wasn't a long-term fit so we became FWBs. We're both free to seek out other dates and know we will likely have to end our relationship once that other person comes along for either of us. It's been 10 months of fairly consistent, weekly hangouts and sleep overs. Basically the same as dating but we're not planning a life together or escalating the relationship at all. We still genuinely like each other and enjoy spending time together beyond just sex.