I have an article, when Ted and Marlo were involved with each other. A crew member who was interviewed said the two did not like each other in S1. Another article(from a magazine on ebay) said, to quote Ted, "We had hated each other." I know actors put their personal feelings aside when working but i have to say Don and Ann were not as "lovey dovey" in the first half of S1. I've never seen Don yell so much. I understand some of the predicaments called for yelling but Don seemed so exasperated with Ann in most of the episodes. The ep where Ann is his secretary is a good example. In the first scene he comes in and kisses Ann on the cheek. Then he yells and then we hear him smooth talking a female co-worker on the phone. Definitely not the Don he became. As the series went on, whenever he was with Ann he spoke slow, soft, affectionate. I think once Marlo realized Ted was TRULY the nicest most sincere person on the set things got better between them. According to Ted, Marlo was extremely difficult to work with and was beyond perfectionist. Also he deduced that Danny Thomas never gave her the confidence she needed as an actress. naturally when Ted was acting himself(he was a very kind man) Marlo thought he was blowing smoke up her a**. ;)