Octavia says to Bellamy "here we go again. Pleading for the life of a traitor who you love."

She refers directly to when Bellamy came to see her a few episodes earlier to ask mercy for Echo's life that Octavia sees as a traitor. By doing this, Bellamy's romantic love for these "traitors" is put forward. Octavia shows that the love she is talking about is the same. It's not very platonic.

It's pretty self-explanatory, I think.

As for Russell, we can interpret it as we wish. But we know that Josephine doesn't love anyone except her parents and Gabriel. So we can assume that her father reminds her of her pain when she lost Gabriel. Which, again, is not a platonic parallel.