I think my 14yo stepson is attracted to my wife [his mother]?

My wife is 33 i'm 25. I think that he is sexually attracted to my wife and i'm not sure that she isn't attracted to him to. I always thought that they've had a strange mother son relationship. My wife will change her clothes in front of him not to the point of complete nudity but he has seen her breast Quiet a few times. my wife is kinda strict on her other two kids both girls but she seems to let him do whatever. He frequently lays in the bed with my wife and she will do things like putting her feet on him. Most boys would be grossed out by their mother resting her feet all over them but he never seems to be. I once overheard him telling his mom that she is sexy. overall they just act more like a couple than mother and son. am I over reacting here or should i continue to monitor this closely