Well then if that is how you feel I would suggest finding out which gender you are more comfortable dating long term and then see if your partner would be willing to either let you have a casual thing on the side every now and then when the erg arises or see if they would be interested in participating in said casual event. Believe it or not there are quite a few couples who do the causal group thing and most that I know have one or two people that are their regular casual additions. Like everyone is in it for the fun that can be had and its nothing more then that.

I can say form personal experience, with the right partner something like either of those is possible with out doing any damage to the primary relationship, yes it takes a lil extra work, but if your willing to put forth the effort the out come is well worth it.