Let's face it, Arnold secretly knew about Helga.
There NO WAY he couldn't have been the least bit suspicious. Too many hints.
-Romeo and Juliet= kissing him a long time.
- Summer Love= kissed him when all she had to do was give him CPR.
- Grandpa Phil pointed it out
-she wanted to help him make Lila jealous by rubbing her feet and combing her hair
- the married episode.. Nuff said.
- saying "whatever you say Helga." Sarcastically to indicate she's lying.
-Arnold saying she's not really a bad person deep nice she's really nice.