i am the cancer that should be cut out

so i had this tiny little crush on a guy from work who is married to a chick who also worked there. and now months later it is apparantly a mutual crush. and the crush is now giant. i am still with my significant other so this isn't going to work. dave knows about the situation and knows i'll be good and try and handle things properly. but i want the both of them. i wish i was in a poly relationship still. life was easier. i was able to go out and date and flirt with people and come home to main person i was with. of course that i wouldn't go further then kissing other people. but it's not how shit works in this long term relationship. i feel shitty like i lead him on which i know doesn't fucking make sense because i thought being 10 years old then me he would just see me as a kid and go on. he told me tonight when we were chatting that he really fell for me. fuckfuckfuckfuckfuckfuckityfuckfuck. the wife thinks this is onesided(me liking him). and i know at like doctor who and rose being seperated by different dimensions me and him must remain that far apart yet that close. i want him with every fiber of myself being i want him but i can't have him. i can't i would emotionally kill myself for it. i can't walk all over the trust that dave has given me. i just can't. but i want to. but i need to be strong against this. i want to ask them both if i could go with both of them but i just can't see that dave would be happy about it. i never thought this situation would come up in a zillion years. i feel like i fucked up his dreams and hopes.