Post ANH and Han and Luke haven't confessed their feelings, but are both trying to seduce each other. Han is more experienced and has all the appeal of an older man, but is a little bit fail-y because Luke isn't sure whether he's just trying to show off his manliness to impress Leia or something.

Then Luke, who is innocent and virginal, seduces Han by sort of turning this up a notch, whilst also doing a bit of cheeky bending over in a nonchalant way, or just happening to have his shirt off when Han walks into a room.... and it works.