The endings of The Science Project and Love Beam No 9.
More specifically for the second one, at the start we see a flashback to when Lloyd was younger and carved "Lloyd Loves Brittani" into a tree. Britanni catches him and he runs away crying. The episode's plot is about her getting hit with a Love Beam that makes her fall for Lloyd. She eventually takes him to the tree and pulls back the branches to reveal Brittani Loves Lloyd Too carved underneath.