I'm no Biologist-- haven't played one for years-- but I think this is how ♂ and ♀ robins make F1 robins.
Seen across the street from the Starkvegas library on the 1st Monday of the month... the book sale day!
I thought I had recorded more than I had-- I'm not familiar with recording on my iThingy. This behavior went on for several minutes before I realized I wasn't capturing it on "film." They were not at all unlike Rocky & Missy's behaviors when the Rockster is feeling ... frisky.