I honestly appreciate your replies ! Thank you guys !
I guess I do need to be extremely honest with her and talk straight and clear.
In the bottom of my confused soul, I guess there's a stupid fear that she might do this by herself if I declare my jealousy issue. Something like "-Hey, it's your fantasy too, right ?".
During some rough time we had some months ago, some day, after sex, we discussed about swinging again and she said that maybe this would be a good way to test our relationship, our feelings. I thought and still think that this is a very wrong way to test a relationship. Later she agreed with this. Since then, our relationship changed very much for the good but I'm still not ready to plunge into this. I did tell her a few times that I would like to find a place for amateur streeptease (not exactly in our city) to see how we both feel after that. This is something I would be ok with for now. I guess this would be also a good way to test my "issues"