Would this be considered cheating?

I met a girl online who works near where I work. Every once in a while we get together at lunch and go places like Barnes & Noble and we play this game like we don’t know each other and are sitting down reading a book and she will give me fleeting looks up her skirt kind of like Basic Instinct. We do this for a while until we are both horny, but then we go back to work and back to our own relationships at night. We have not done anything else. Do you think this is strange or considered cheating?