I know its late but, its not always a bad thing to have a boner. Thats the way my boyfriend was about it with me at first, he would end up making space, like stopping a hug mid-way through, but after i while he just got used to it. especialy after i told him to stop worrying, its normal and i dont mind. See if she cares, that would help you :) i hope i did some help for the future:)
training your mind is not hard. but try to think about some thing that will get ur mind off of it that is what i did and it works. just keep ur mind off of it as much as u can that is the hard part.
try to think of anything not moving and have no sound like chairs .painting...etc ..& try not to communicate emotionally too much with your partner at this early stages (huggin,kissin)
omg think of something real nasty or ugly
or something that turns you off hope i helped
i dont think she's gonna mind xD common shez gonna b happy that shez turning you on xD
Oh gosh...down boy, down!!! Phew, there we go... :3
You need to train your mind to control it.