Replying to your message:
Literally, "haa... haa... *repeat*"
It means excitement, basically. Or panting. Like when a person gets excited (possibly... in a sexual meaning), they get out of breath and start haa... haa...
I used the emoticon referring to the sexual harassment scene in the previous episode, where, well, the brother starting getting excited and "haa... haa... haa..." over the protagonist.
