How he leaves out that it's her: a few months ago, he tells me he finally meets a bunch of coworkers he likes and goes out with them for drinks. I have to ask more info about who they are because such details don't concern him apparently. I gradually learn that he hangs out with them at lunch

A month passes and he texts me one day asking for advice on supporting her through the death of a colleague's uncle. Eventually I have to ask and find out its the female one. Knowing they met as a group, I ask him what the other two guys are doing to support her. He says he doesn't want to tell them because it's her personal matter. At that point I'm confused about the dynamics so I inquire further and find out the both of them lunch together daily withour the two guys. Before this I was already wondering why he stopped texting me during lunch but I dismissed it as giving him space. We had a mini quarrel over this where I made my point that details are important, but made up.

There are other stuff but over the last 2 months, he's become less responsive, usually replying with 'Lol' or 'I'm tired' then apologises. There's not much I can do when he's not online. One of those days, he sent me a picture of a massage device and said a 'coworker gave it to him'. I immediately suspected it was her but said nothing, hoping he could tell me on his own. He's been using it to relieve stress and really likes the device. Today, after some unbearably forced interactions, I finally ask him if it was that coworker that gave him the device as a conversation opener He says yes. And then he adds on and tells me that he introduced her to my favourite idol, completely unsolicited. It's the first time in a long while that he makes effort beyond small talk, but it's about her. He tells me that she's a fan of all the things I like too. But In my head I'm questioning why he's bringing it up now rather than before when I would have liked to know.