Yeah, it's a little disturbing, where these things seem to be coming from. Just not disturbing enough for Soldat to stop. In this, they are being supremely selfish.

The awkward explanation gets a small, sweet kind of smile. "He's your favorite person," Soldat summarizes. "I understand." They've got memories of Steve, now. He might not have been their mate in that way (they, uh, don't think anyway; honestly, there could be a bunch of sex-memories and Soldat would never know, but it doesn't seem like they had that kind of friendship?), but he was special. "Now you have it, and you won't ever forget."