He does this sometimes, but I very rarely look at him unless it's small talk or about something fairly mundane. I've appreciated the few times he's asked me to look at him when I was especially deep in feelings of shame. It's like it gives me "permission" to look at him when I feel like I don't deserve to or I'm not worthy or I'm too disgusting or whatever, like he's telling me he doesn't feel that way about me. And when I have actually been able to glance up and see him looking at me I do feel "seen." I feel exposed and that he's still looking at me unflinchingly.
When someone does something embarrassing or shameful in front of us, we tend to avert our own gaze.
When he's still looking at me like that it feels like he's telling me that he doesn't see it as shameful/unacceptable, that he isn't disgusted by me, that he isn't angry, that he isn't "rejecting" me, that he isn't hiding judgment or disdain.
I kind of wish he would do it more often.