The two of them have a habit of "helping each other out" in the hold. Manson has a crush on Hartnell but thinks that he would never reciprocate. (Maybe Manson's internalized homophobia is mixed up in some internalized ableism – he thinks that he likes men because he's "wrong" but Hartnell is smart and good, so he must be different.) Post lashing, they take comfort in each other and it leads to a first kiss/feelings reveal.

If that doesn't appeal, literally anything with these two! Give Manson a boyfriend!