Soren was actually more interested in watching them. He loved Cass, but it was different from what they had, and he loved watching them together. He didn't feel jealous, didn't feel upset - he felt happy that someone could make Cass happy in the way Henn did. That, and he cared about Henn in his own way too, so watching them play like overly contented cats made him grin, even as he rocked his hips into his hand.