Not when you've got the skillz.
Except for those rare instances when the guy has a bazooka or literally a foot-long between his legs. A very small number of men whose pants I've gotten into have members which fit that description. They make your eyes pop and your salivary glands go into overdrive. But in reality it's sad for somebody who's truly massive down there. Being "average" I'm glad to not have to know what it's like to never achieve complete penetration or - succeeding at that - to not be able to experience a full-tilt BJ or saw away wildly in a tight a-hole.