Marking her territory or trying to be my friend?

[Anonymous]

This guy I'm best friends with (and have been intimate with before. We can't be together as I'm in an open relationship) is dating a new girl and she is coming on really really strong to me. He and I talk daily, and hang out a lot. She msgs me daily and even tells me when she's with him or that she laying on bed with him, etc... she knows we are very close, do you think she is trying to mark her territory, trying to just get on my good side, what? We barely know each other so it's not like her and I are friends. She does NOT know that he and I have a past

[Guy13]

Definitely marking her territory and trying to put some separation between you two. He is eventually going to have to choose between you two.

[Kaneki05]

She wants rid of you for good reasons by the sound of it.