A cat beside you is not necessarily keeping you at a distance. It may be choosing company without the squeeze of a lap, enjoying your presence while keeping control over its own space. That can be affection, even if it looks nothing like the cuddle you had in mind. Cats get a vote.
The most telling signals often come in combinations. A relaxed cat might settle near you, give you a slow blink, then rub its head against your hand or the furniture around you. That rubbing can leave scent from facial glands, a form of scent marking associated with familiar surroundings and social contact. A slow blink has been studied as a friendly signal in cat and human interactions, although no single gesture proves what a cat feels. Look at the whole animal: a loose posture and a willingness to remain nearby suggest something different from a tense body and ears flattened back.
An empty lap is a poor measure of your relationship. Some cats dislike being held, run warm, prefer a stable cushion or simply want an easy exit; individual temperament and past experiences can shape those preferences. Give your cat room to approach, offer a hand to sniff and let it move away when it chooses. If its behavior changes suddenly, especially alongside hiding, reduced appetite or signs of pain, ask a veterinarian for advice rather than assuming it is just being aloof. The reward for paying attention is a clearer conversation, not necessarily a cat on your knees. So, where does your cat choose to sit?