Sounds like a mental block. Are you worried about anything? getting pregnant, bills, incest, or life position? You might look inward at yourself and see if there is anything your putting infront of you before come. Clean up those issues no matter how hard they are to deal with and you might be able to let go enough to just enjoy yourself and let your body climax. That tickelish feeling is probubly the right direction, then you might controlling yourself out of it...why? Just my 2 cents...I am not a shrink