There seems to be a big piece of info missing...did the attempted kiss occur at the party...or afterwards at the sleepover...is it possible that they were together at the party ,,and totally seperated during the sleepover..
if it was at the party,,then are you going to ban her from all future parties....
I can see being bothered by the sleepover..but you should be proud she said no...
rather than banning the boy,,welcome him into your home...insist that any time they spend together be chaperoned,,his house with parents home...or your house......
otherwise it will just be another boy..another grounding....
My 17 year old daughter was seeing a guy that I didn't like, rather than trying to stop it..I told her to invite him over for family night...we watch movies, play board games..whatever..but it's a good time to talk with yur kids in a relaxed atmosphere....
so anyway...he came over one night..and we all sat around just talking,, I kept binging up the good subjects...cars, speed,,,,all the things teenage guys love..I fed him the rope and he hung himself....LOL..'till he was finished talking about racing, and thru bragging himself up.,,she was no longer interested in him....
plus if ya get on the boys good side, he will want to stay there, and will try his best to not betray your trust...
therefore I vote for lifting the grounding, restoring privileges, and inviting the boy over for family night......
