I just love the idea of Polin having their first kiss in episode two because it creates an opportunity for a slower build-up in intimacy than we've seen in past seasons. Simon and Daphne's first kiss is in episode 4 and their first time is in episode 5. Kate and Anthony have a longer slow burn and build-up in tension, but when they have their first kiss in episode 6, it escalates quickly to their first time in episode 7. Even Charlotte and George kiss in episode 1 and have sex at the end of episode 2.
Having Pen and Colin kiss in episode two gives the show a bit of breathing room and could freshen up the structure of the show. They have their first kiss in episode two, which leads to sexual tension in episode 3 that then gets released in a more passionate make-out session (episode 4, carriage scene), which shifts their relationship dynamic and then builds to their first time in episode 6 or 7 when they confess their love to each other (mirror scene). And this kind of structure where the moments are more spread out adds to the themes of growing individually and with your partner.
