Part of composing a picture like this is the connection between the two subjects, or really three, but let's stick with the two that are directly visible! We know that they're connected by the pose and the partial embrace. She's in light colors against a black background, and she looks maternal. She looks like she's dressed for the part. He's in dark colors against the dark background fading inseparably from the background and dressed in street clothes. Her soft tones and curves are interrupted by his harsh tones and the (too) white t-shirt.
I'd like to see a separation light on (at least) him and/or a different background. She wouldn't be hurt by a splash of separation light, but her light colors don't create a problem.
I'd like to see him dressed differently, but that gets into personal style with the couple.
Overall, I'm having a hard time putting my finger on whatever else is sticking in my mind. I think it's the visual balance that's too far to the left. With a different color background, the balance would shift. But with the background black and him mostly black and her in a light color, everything is shifted to the left.
It's not even about the pictures; it's about the memories and communication.