Hi,
Most likely, those spots are erogenous zones on you, meaning that when massaged, they turn you on BIG time. Some other not so normal spots that might have the same effect are your neck, ears, chest, and scalp massaging. For my boyfriend, whenever I suck or nibble on his ears or lick his nose/nostrils (sounds gross, it's not) are his erogenous zones/spots.
Hope This Helps!! =D
Edit: Any spots on your body that have a lot of nerve endings will have the same effect. Surprisingly, the feet and back (especially lower back) have tons of nerve endings that make when massaged, make you more sensitive "down there."
Erogenous Spots on Guys- ears, neck, head, chest, nipples, back, and huge shocker, butt, penis, and balls (all when massaged, kissed,licked, or nibbled depending on where)
On Girls- nape of neck (breathing on it drives girls wild), boobs, nipples, wrists (sounds odd, feels GREAT), butt, feet, back (esp. lower back) back of knees, inner thighs,, and huge shocker, vagina (all when massaged, licked, kissed, or nibbled depending on where)