Throughout the Series
During Season 1, Otis and Ruby hardly interact except for when he and Maeve will help her identify the person who sent the whole school a compromising picture of her (Episode 5).
While their interactions in Season 2 are initially non-existent, their relationship takes a most unexpected turn when, following episode 6 (and a party a little too alcoholic), Otis wakes up in his bed with a hangover and Ruby by his side. She casually confirms to him that they had intercourse last night but that she cannot find the condom, which worries Otis greatly. She will later admit that she is not sure that their intercourse have been protected. The two then go to a pharmacy to get a morning after pill. If Ruby is reluctant at first to enter it, Otis' arguments will eventually convince her. During the questionnaire to obtain the pill, Otis learns from Ruby's own mouth that her father has been suffering for one year from "multiple sclerosis" (MS), a disease affecting the central nervous system and which can lead to permanent physical incapacity in the patient and in the worst case, his death.
After getting the pill, Otis will worry about whether Ruby was consenting at the time of their intercourse, to which she will answer yes, justifying this by her habit of sleeping with "nerdy boys" when she is sad, which gives her for a short time the feeling of being passionately loved. Otis reveals to her that this was his very first sexual intercourse and asks her about the level of his performance. Surprised, she replies that he was not great but not terrible either.
Otis asks if her father's illness is causing her sadness. She answers him yes but immediately diverts the subject of the conversation by accusing a lack of symmetry in her eyebrows after epilating them. Playing the game, Otis replies that he finds them very even. Ruby smiles at him and thanks him for accompanying her, adding that most boys are not as considerate as he is. Their arc for this season ends with Otis driving Ruby back on his bike.
Season 1 Screencaps