Ok , I tried to explain to many girls what it feels like for a guy when she gives head - and over the years, I came across this one perfect example thanks to an open minded woman I met years ago:

Have your guy give head to your BIG toe (choose one from either foot) - preferably while you are wearing a THIN Sock with an opening for your Big toe to pop out. If he's really imaginative, he'll forget it's just a toe and can go "down" on you for a long time, driving you wild with pleasure for a long time or until his mouth gives out!

While your man is making love to your toe, licking it, and slowly enveloping it with his mouth... stroking it in and out - you'll get the same feelings as a man does when a woman gives a man head. OF course, if you got a lot of calluses (hard skin) the sensations won't be the same. The "thinner" (soft skin) toes will get all the sensations I'm referring to - but the small toes just aren't as sensitive, and lets face it... the Big TOE is large enough to substitute in size for an average size penis head.

Oh, and the thin sock is so your FOOT is desensitized as much as the penis shaft would be. Not totally insulated but just dulled enough so you feel pleasure only in the stroking and the pressure applied by "his" hands as he caresses you while giving your toe head.