First thing to consider here: Jean is a telepath. That means she doesn’t have the liberty of saying stuff like you and I would have exactly because her word carries “authority”. When Jean says: “don’t be silly, of course she loves you”, it means much more than if we’d have said the same thing.
Forge knew that. Again: he framed the question by pointing it out.
So, no, there’s nothing Jean could have answered that wouldn’t be a betrayal of Ororo.
That being said, I’d have been really angry, for me and for Ororo. For me, because, how dare Forge put me in that position? And for Ororo because why was he going behind her back instead of talking to her?
Again: the way Forge framed the question wasn’t of a friend who needed advice or reassurance. And that’s what makes it so insulting and what would have made me so pissed and protective of my dear friend.
But Jean is better than me. She probably understood that dating a superb woman like Ororo cannot be easy for any man who isn’t named T’challa (and even for him, it’s not like it’s a breeze either). She probably saw that Forge was insecure and he was trying to solve the problem by removing his doubt. She probably even felt sorry for him for misplacing his feelings and his reasoning so badly.
My empathy would only come after that conversation and it would still be tainted by a lot of judgement. But Jean’s is her second nature. She truly sees the best in people even when they’re behaving in a really sh***ty way. When I took that into consideration, I was finally okay with the way she replied: she didn’t betray her friend and she didn’t berate her friend's lover either.
That being said, yes: I do miss Jeannie and ‘Ro being friends on panel. I’d be over the moon if instead of Scott showing Lorna the Treehouse, Jean was showing it to ‘Ro and the scene ended with Ororo wishing her good luck and thanking her for restarting the team again. Bonus points if there was a hug! :)
And I said it here before, but I’d love to see Jean showing up on Mars to talk to Ororo and check if she was doing okay, knowing Ororo is strong enough to pull her new role off, but still offering to ease the burden by listening to her or talking about something else, you know?
As for your ideas about Jean and Ororo, please, share them. Ororo has a special and really big place in my heart too and I’ll love to read them. :)