He loved her, and sometimes he was sure that she loved him back. He wouldn’t allow himself to let his guard down and be with Hawke because he didn’t feel like he was enough for her. She was a hero, and he didn’t want to fall in love with her, only to have her move on to someone else who was better than him. This was why he always shrugged off her flirting. This is also why he eventually left her after the fall of the Chantry. He didn’t think following her around, and always wondering “what could have been” was very healthy. He still misses her, and he always will.
Since she is not very good with the new situation of her being paid money, she often wastes quite a bit of her wages on books. Varric helped her learn to read, so she’s his best customer.