If he were as clever and observant as she thought he was, he would know she’d tried to flirt with him in the past. Artemis had never come out and propositioned him -- nothing even close to what Purity did, nor had she been in a private, romantic setting as Honour had in the Canterlot Rookery's 'Well of Life' -- but she had made some moves. Moves to which he had previously been oblivious, apparently owing to them being uniquely Equestrian and not part of his peoples' repertoire, but given what Honour said he had learned, he surely must understand what she'd done by now. Even that unintentional incident with the Maypole dance should have been a fairly obvious early warning sign.