It wasn't that Rodolphus particularly felt he wanted an ally in Severus Snape (at least not to the point that he himself would go out of his way to get it) as he was quite happy on his own with his numerous mind games and followers. But Snape was a member of his past, the scrawny boy who tagged about his and Lucius' gang and later the seeming protege of Voldemort himself, one of the inner circle, torturing alongside Rodolphus. That meant something. So, he decided to give in and give the sallow man a visit.
Apparating into Spinner's End with such finesse that he apparatted right onto an arm chair, Rodolphus tilted his head in casual greeting, "Severus."