Attraction takes time to develop. Perhaps if you’ve grown up with the person, you’re more likely to feel attraction than lust, although they’re not mutually exclusive!
According to Dr. Helen E. Fisher, an expert on the biology of love and attraction, the answer might in fact be up to three people at once. In her book (Why We Love: The Nature and Chemistry of Romantic Love), she proposes that the human brain has evolved three core systems for mating and reproduction – lust, attraction and attachment – and that love can start with any one of these three feelings.
Lust
Lust is sexual attraction, the need for sexual gratification. The sex drive, or libido, evolved as the primary means of getting out there with as many partners as possible. We are, like all living things, designed and driven to procreate. This is probably the most common system we start with. Admit it, a guy probably strikes up a conversation with a girl because she looks cute or hot and he wants to get in her pants, not because he wants to take care of her (Attraction) or because he had a deep feeling of union with her (Attachment). This is what pickup lines are designed to do: initiate contact with the ultimate goal of hooking up. I’m not saying lust is bad; it’s just arguably the most common way relationships are started, regardless of whether or not the pair actually hooked up.
This also works the same way for girls too, okay!
Attraction
Attraction takes time to develop. Perhaps if you’ve grown up with the person, you’re more likely to feel attraction than lust, although they’re not mutually exclusive!
Attachment
If these three core systems are out of sync, then one could potentially lust after one person, be obsessed with another, and have deep feelings of union with a third.
It looks like love isn’t just less than three (<3) after all.