Can athletes foot cause groin lymph node pain?

I doubt it: Usually lymph nodes don't swell in response to fungal infections. I would have it looked at as that could be caused by a bunch of different thing from simple things like shaving to horrible things like cancer.

GroinLymphadenopathy: Athlete's foot (tinea pedis) doesn't by itself cause groin lymph node pain, as it is a fungal condition limited to the skin--unless there is concomitant foot infection--. Pain in a groin lymph node suggests inguinal lymphadenopathy, w/c is usually caused by infection or metastatic tumor/malignancy in the foot or elsewhere in lower limb, in w/c case it is imperative to seek prompt medical attention.