Potential advantages
Existing trust can make communication and comfort easier than with a stranger. Some people also value flexibility, sexual exploration and companionship without the expectations of a conventional committed relationship.
Potential drawbacks
Friendship can be affected if one person becomes more attached, feels jealous, or interprets intimacy differently. Ambiguous boundaries can also create avoidable stress around dating other people, social events and communication.
Who may prefer this structure
People who genuinely want a casual relationship, can communicate directly, and do not view the arrangement as a hidden route to commitment may find FWB compatible with their preferences.
Who should be cautious
If you already want exclusivity with the person, feel unable to discuss boundaries, or know you would be distressed if they dated someone else, the arrangement may not fit what you actually want.
Questions worth checking together
Before relying on a label, compare the expectations underneath it. Are you both using “friends with benefits” to mean the same thing? Is the arrangement exclusive or non-exclusive? What level of friendship and communication feels normal? What information would either person need if another partner enters the picture? Those questions are not meant to turn a casual relationship into a formal contract. They are a way to surface assumptions before those assumptions become evidence in an argument.
Revisit the definition when behavior changes
A label that fit three months ago may stop fitting when contact, affection, exclusivity or future plans change. You do not need to renegotiate every small variation, but a meaningful change in the relationship is a good reason to ask whether both people still understand it in the same way.
Labels help describe a relationship, but expectations are specific to the people in it. When something important changes, a direct conversation is usually more useful than trying to decode a rule from the internet.