Background
I have a friend I'll call Hamlet that I've known for quite awhile through school. He also has a girlfriend I'll call Ophelia that he's been dating for over 3 years.
I've known Ophelia for as long as they've been dating and don't like her at all. I think she's very immature, insecure, and self-centered.
There's also a group of acquaintances I associate with regularly that are friends with Ophelia. I consider them decent and trust their judgement and observations for the most part.
Situation
Earlier this week I heard from those acquaintances that Ophelia had apparently ceased the use of contraceptives. They said it's "an effort to become pregnant so that Hamlet would be 'forced' to continue being together with her." Further, they said she has taken a test and is pregnant.
Now, this is a pretty huge claim, and one that I don't take lightly. But why lie about this? This seems like something Ophelia would do. I'm still cautious that it could be a ruse, although this is unlikely.
Summary
I'd like to tell my friend Hamlet about the rumors I've encountered and the strong possibility that Ophelia may very well have done something malicious. I feel I owe it to him so he's not potentially surprised later or unknowing of Ophelia's prior spite. I think these claims are very likely to be true, so it's not like I'm just dropping a stray rumor.
I feel that Hamlet might be upset once he discovers everyone but him knew about the situation. I think it’s important I tell him now, so he has time to prepare for this and not have a sudden future surprise and take it out on the people who knew beforehand.
It’s not just simply telling him a rumor is going around, but that I personally believe it has validity.
With this in mind, how can I gently tell Hamlet that Ophelia likely 'let' herself get pregnant whilst conveying that I'm on his side and also didn’t have bad intentions?