Astro Sprout and Cosmo

Cosmo is Sprout's best friend.

Sprout and Astro have been dating for 4 years now.

Cosmo has brown hair, and it's short but thick and slightly curly. Cosmo is always dressed in something cute, she likes to wear sweatshirts and colorful knee-highs, white fluffy leggings and dark brown sneakers.

Sprout has straight, light green hair, he likes to put it in a bun, he always dresses in regular clothes - a T-shirt and pants

Astro has blue hair and likes to wear something like pajamas or just knitted clothes.

In the last few months, Astro and Sprout have started showing some sort of attraction, haven't they? But Cosmo has been pretty much ignoring it and just continuing to interact with them as friends.
In the morning, Cosmo was sleeping in his room, covered with a blanket and hugging a huge plush seal, and suddenly someone knocked on his door and Cosmo woke up from the knocking, since Cosmo was sleeping in his underwear. He quickly threw on a T-shirt and shorts, went to the door and opened it, and there was a sprout, Cosmo yawned and said
Cosmo: What do you need?