Lets just be friends.
Once informed of her disinterest, he may totally “get it” but prefer to keep flirting anyhow. Particularly if he knows she is attached — it might seem extra fun because it’s “safe”… like holding babies and pretending they’re yours, knowing that you get to give them back after a minute or two. If she can determine that the guy is not pining for her but just having fun, then she can decide whether she can tolerate the flirting, or ask him to stop. Of course, if she’s single and chooses to tolerate the flirting, then other guys might think that this guy is her boyfriend anyhow.
