We've all heard the story before.
Boy meets Girl at 13th annual Delta Sigma Theta kickball cookout and soft-boiled egg eating contest; an event where all the proceeds go towards finding a cure for clit gout. Because #allclitsmatter. Girl is intrigued by Boy's use of "disabuse" and "Caucasian motherfuckers" in the same sentence, and Girl favors Richelle Carey, so Boy is interested by default.
You also happen to know both Boy and Girl pretty well. They both would be considered friends. Which is big. And rare. Because you have very high standards for who you consider to be a "friend," and you're perfectly willing to bore people to death with the unsolicited details of those standards. Anyway, since Girl is a friend, you're aware that she's a relatively "nice" and inexperienced Girl looking for a nice Boy. And, since Boy is your friend as well, you're aware that Boy has some aintshit tendencies when it comes to women. And you know, with 100% certainty, that if Boy and Girl get together, Girl will catch feelings for Boy. And Boy will catch…nothing. Except Girl's ass a few times a week for the next two to four months. And a few "Hey. I haven't heard from you in a while. Everything ok?" texts from Girl after Boy finds a new conquest and drops off the face of Girl's Earth.
Anyway, Girl knows you know Boy. And asks you about Boy. ("Hey, what's up with your boy, Boy?") Are you obligated to tell Girl about Boy's aintshitness?