blowjobs

Is it just me or does anybody else get a case of the noodle arms, when you're trying to give your man head while he's laying down? Tonight I was trying to be all spontaneous and go down on him, but I kid you not after 20 minutes he just tells me to stop because he can feel my arms shaking the bed....He normally lasts a long time, so I rarely do go down on him for that very reason, but it feels so one sided. Am I the only one?