I've had this happen to me. If it happens again, 2 options. Either have her blow you, or find another place you are sensitive (such has licking your nipples or biting your ears) and have her focus on that. This will help you relax and you can completely ignore your dick, then after she's been going at it for a little bit, the relaxation will have helped you get hard.
I would almost guarantee this is all mental. Do you have this problem getting hard with porn? If not, its mental.
I would almost guarantee this is all mental. Do you have this problem getting hard with porn? If not, its mental.