Maybe it’s because they think it’s “gay”. I’ve learned that most straight guys prefer quick “blow and go” situations.
In other words, they just want to whip it out, let you do your thing for 5 minutes or so and then release. Here’s what I do to get them off fast and make sure they come back for more. Take a small amount of silicone lubricant and place it on the tip of your tongue. Conversely, you can put some on the palm of your hand. This helps work them up quicker and nut faster. The last thing a straight guy wants to see is his man juice covering your face or chest. In fact, they don’t want to see their semen at all.