now shes seemingly playing hot/cold games, but i wont have it

things stayed pretty high frequency up until last weekend. she ran a half marathon and decided to text me in the morning afterwards. I didn't respond for 7 hours because I was starting to get the side I was becoming her boy toy. ever since then her texts have fallen way off and just the other day I went 72 hours without hearing from her and when I did it was just a simple invite to go run. I turned it down and then the next morning she asks if I want to meet up with her at a starbucks. we kill an hour there and go our separate ways. she mentioned that ( during one of her complaining rants) that the last time she had a sit down meal was with me 3 weeks ago when we got Chinese.* so the other day she runs by my work after I could not meet with her and proceeds to randomly drop off her sweatshirt in my vehicle before asking if my girlfriend wouldn't care. I said yeah thats fine. I ended up giving it back to her yesterday.* and then yesterday I had a chiropractor appointment and she says she wanted to run from her house to the office and meet me there so I can drive her back home. I didn't think much of it but thought it was kind of weird and perhaps she is just using me. she invites me inside and the husband and two kids are there and I have some cake and coffee before going . as I was about to leave she was leaving to pick up some pizza and asked if I wanted to ride with her so I said I don't care sure.* and as of today I have not heard from her. I find her behavior very weird .* I have no interest in breaking up a marriage so I don't need a bunch of posts telling me to stop associating with her but my main objective here is to figure out what she is thinking. if she thinks she can play hot and cold with me I'm not going down that road.. too old for that