Good question. Hmm... No handfeeding, no warm food, no snuggling (you can preen his head and neck, but nothing else)... It's hard to say because romantic gestures and non-sexual friendly behaviours can be quite similar. Maybe try to make your together time about playing, dancing, singing, training, etc., rather than cuddling or being calm and intimate together. You want him to see you as a playmate, not somebody to snuggle with. Birds who are strictly friends tap beaks, wrestle, fly together, explore, sing to each other, dance, destroy things, show off, and occasionally preen each others' heads, but they don't necessarily sleep together or cuddle. That's what their monogamous mate is for. I personally wouldn't stay away from him for a few days, as this can cause anxiety and feelings of betrayal. When he's out with you, make sure it's nice and bright so he doesn't think you're trying to lure him into your love nest or something (gross, yes, but the only time it's dark in the wild is at sleepy time or when they're inside their nest). Also, make sure he doesn't go near your face, chest, or shoulders. He can hang out on your forearm but no higher. Bringing that close to your face is far too intimate. Full body contact is a no no (except with my birds because they know I'm not a romantic partner).
It's hard when keeping single birds (i.e., a one bird household) because you have to fulfill all their social needs, including that of a mate. Most parrots are monogamous, and they have a strong emotional and instinctual need to find a life partner to raise their young with. Monogamous birds with such long lifespans...with a variety of these species, if the sex ratio is skewed, they'll settle for a same sex partner to raise young with (this is seen in some species of albatross). This is one of the reasons I believe in keeping more than one bird. They don't have to be the same species (they should be of a similar size, personality, and beak strength), they just need to be able to do bird things with them. Obviously I'm not suggesting to go out and get another bird, but that's something to think for in the (distant) future after you have a hang of things.