New play behavior

I'm always watching Marley when she plays with other dogs. She likes to wrestle and I'm always concerned about it getting out of hand and developing into a fight. I look for "balanced play" where both dogs take turns being on the bottom. This is especially important because her favorite playmates are part Chihuahua, which means they are usually smaller than her and she can easily dominate the play.

Marley is very good about holding back her strength (or self handicaping) in order to play with her little friends, however sometimes she needs a quick reminder that she needs to hold back. One of the commands we have worked on is "lettem up" (why are all my commands all one quick slurry word?). When ever I notice Marley is keeping a dog down longer than I or the other dog owner feels comfortable I say the command and Marley jumps off and waits for her playmate to get up and they then continue playing. This didn't take very long to teach because she quickly realized if she didn't respond to the command play would stop immediately.

Marley has recently started exhibiting new odd behavior that I'm not sure how to interpret. About two months ago we met Cleo, who is about 19lbs. They ignored each other, except for dominant marking in the park.

Cleo

Last week Marley finally noticed Cleo and she went up to her and exhibited puppy-like behavior, such as lip licking, nipping around the lips, lots of play bows and little sharp excited yips. If Cleo reacted, Marley would swing around slightly and body slam Cleo. This continued until Cleo started to chase Marley.

Cleo playing with her favorite toy.

When done playing chase and drank water together. Then they started wrestling, which was interesting because while they look similar in size Cleo outweighs Marley by 10 lbs.

Marley wrestling with her new BFF, Cleo.

I found this interesting because I have not encountered that type of play solicitation that merges puppy like behavior with body slams. At this time while I closely supervise and I will step in if the play vibe changes, I'm interested in finding out if I should be more concerned about this behavior.