Didn't they already have sex or are they just still shy about these things?)

Not yet ~ well, not all the way. In the novel they flip a coin before deciding who will bottom first. In this manhua in the raws it’s suggested at the end of chapter 130 and begging of 131

Raws of 130 (when they flip the coin) https://www.cocomanhua.com/14394/1/134.html

Wow, thanks)

So who ends up as the bottom?

First Hank bottoms, then later junior bottoms. Those are the only two times it’s mentioned in the novel

Ohhh switch couple!!! Thanks :)

Hi!
where did u read the novel?

It’s not fully translated into English yet . You can find it here https://www.novelupdates.com/series/a-lucky-coin/ and the machine translation here https://jpmtl.com/books/1715 (the translation is poor quality but you can get the idea of the storyline)

thanks!