Indeed, you're going to have to get to the bottom of what exactly it means "weird feelings".
As for your wanting to know how it goes for other people - I think it's good that you might have your first "poly experience" with someone you already know. Although it is my first "poly" relationship since I have known my husband, I have actually known my boyfriend longer than I've known my husband (and been "involved" with him) so it was pretty easy for me to deal with it internally. I have checked in with husband periodically and he seems ok knowing that i'm still the same person i was yesterday and that my other relationship has not sent me into a tail-spin of self-neglectful behaviour, which is something i used to tend to do whenever embarking on a new relationship or even a casual affair with really great sex.
You know yourself better than we do, so only you can determine if your "weird feelings" are just a product of going down the road less traveled or if they are true gut-feelings that signify a "red-flag" of some sort.
Last edited by NeonKaos; 09-25-2011 at 09:38 PM.