How they compare
Both are built for discreet affairs, but they charge very differently.
Ashley Madison is the best-known name, with privacy features to match. Women use it free; men buy credits to start conversations, from about $49 for 100 credits up to around $249 for 1,000 at the time of writing.
Heated Affairs is the FriendFinder network's affair site. It's free to join and browse, but messaging needs a Gold subscription, which renews automatically unless you turn it off, and activity can be thin outside big cities.