I don't see how they're acting like jerks. The decisions they've made have mostly been because of peer pressure.
Harry came across as more of a jerk when he treated Gwen like she was a prized trophy when talking to dear old dad.
Peer pressure shouldn't be an excuse. I said that after having watched the following episode. Peter and Gwen almost kissing shows a disregard for Liz and Harry's feelings. Maybe not outright jerkishness, but still.
Harry's is pretty blatant, I'll give you that. Kind of reminded me of the first Spider-Man movie where he told Mary Jane what to wear in hopes of impressing his father.