Interesting that OP stated on another board that it is illegal for a 23 yr old to date a 17 yr old but not thinking of the consequences of a 13 yr old dating a 16 yr old.
Anyway guys aren't the candy store where you go in and pick this one and then that one.
YOU have to decide who you would prefer to be with. It isn't good to get into a relationship only to break it off for someone else any more than it is okay to cheat on the one you are with.
You got into a bf/gf thing with this other guy so you either break it off and see this one or you do the right thing and see the relationship you are in through.
Also I can see how some got confused with your cousin thing since you used txt and didn't use punctuation