Girls, girls, why in the fuck do you suggest or even plant a seed in dumb boys' brains about threesomes and open relationships??? it NEVER works unless you are a completely free spirit/polyamorous yourself! many partners suggest this to spice up their sex life or to be edgy and cool, and then bites them in the ass when they realize they don't want that.

I think is a bit immature to suggest an open relationship and talk about threesomes, then chicken out, and be all butthurt when he kisses someone. That is just obvious psychology.

I understand that you closed the relationship and agreed to be exclusive, but the seed was planted already, it grew and impacted your relationship. I don't see this turning back happily for both you, since everything that is fundamental in a relationship was violated (expectations, trust, loyalty, cheating). Next time you're with someone, think about what you really want in a relationship and from your partner before you suggest crazy shit just to be "open and edgy".