I feel looking at opposite sex is harmles, as long as nothing more goes on. if it does, tiem to end.

I agree with that too, it is unhealthy to be controlled and to control. Looking's normal I say.

ya, it also helps to pick the right times and ways to look at others,   at least when you are with a significant other, don't just ignore them and keep checking out others!

I feel its okay to look.
as long as it doesn't turn into anything else.
But i completely understand if a girl is a bit irritated by it.

Totally agree.
But some take it completely overboard on the lack of trust.

I think its ok to look, and I wouldn't care too much.  When I look, I don't make it obvious xD

Oh I don't know, I like to take a good look at nice males walking by often enough. lol 

There is normally a reason for insecurity, often leading on to jealousy though and is normally caused by circumstances which have thoroughly caused grief or hurt to a person, either mentally, physically, such as a previous partner having affairs.

There are always people to talk to though, because there is always a way around it, just that if it's a case of feeling insecure because of previous happenings, people aren't able to put things into perspective so well. it can always be resolved to make you (as in people generally), happier though.