Trap is a pretty well recognized sub-genre of anime. As you can imagine, it encompasses a wide range of behavior, from accidental to malevolant. There are several in "You're Under Arrest", for example. With lesbian relations pretty well accepted that gives a lot of room for 'meet cute'. There are bad traps, often deceiving people for monetary gain or the plans to some big secret. Lots of 'trap' art on dA. There was a manga I was following for awhile over there, about a princess kept locked up so she will remain pristene. Her attendents are all female, of course. Except for her primary maid who just happens to be a male in disguise so the foreign power can kidnap the princess. Naturally the 24/7 female impersonation has brought the maid to a point where she/he is questioning everything. I lost track of it so I haven't a clue what happens. So what context you use it determines if it's an insult or not.