Continuity mistake: When Robin steps foot into Poison Ivy's lair she is laid out on her flower bed. If you look at the sleeves of her costume, the ends of the sleeves are fringed in a simple leaf like design. Robin spurns Poison Ivy's affections, and an enfuriated Ivy pushes him into the lily pad pool. She is then confronted by Batman, and a soon to arrive Batgirl. Now - look at the huge, obvious, black rubber "thorn" bracelets that suddenly appear on each of her wrists.
Question: What happens to each of the women at the end of the movies? Each movie has a completely different love interest, we're left to believe that they have bonded and are in love and set for a happy ending, but by the next movie, that woman is gone with no explanation and he's chasing after someone new.