Hello all, I need advice

Hello to all. Im new in the forum. Its a cool place. Im 25 year old and have a pretty 25 years gf with really good big tits and nice ass . Im getting really horny from her but im getting ore exited if i imagine about her with big cocks and see her face all in pleasure and her beautiful pussy ( witch have nice big brown lips) stretched with bg cock. From a long time i have this but with the years i realize i like it more and more first time i found this was on the sea vacation when i told her to go without bra on the beach, i got really big bone to think how every one see her nice tits and how they like them. With the time she told me that we are going to be forever together and she have to try another things ( dicks) and i bought her big black dildo almost 21 sm long and thick she like it so much and fill her tight pussy yeaa.... i cant fill her pussy every time.. some times its so tight and wide... and fro myear ago she told me when she is watched porn and i spy sometimes what he is watched and there is search for big cock/monster cock/ gangbangs and more than one guy fuck one girl... Do you think she will be okey one day to told her that i want to come with another guy to fuck her together and how to tell her... She loves me so much and tell me she dont need other but in the Bed i think its okey to fuck other if both of us are okey with that... and i know that if i blindfold her and someone put his big hung dick in her she is about to get wet and crazy..