Giving him a hand-job, then went soft?

It's very common. He was probably nervous and thinking about a million things.

If it's the first sexual thing you did together he could be worried about you not liking it. He might have been worried about going too early if he's inexperienced. He might have been worried about being late for work. Tons of things that can cause it early on in a relationship.

I wouldn't take it personally.

That's normal sometimes. In the back of his mind, he was probably worried about being late for work. I wouldn't worry about it, moving forward is always good for a guy. He's probably not even worried about it. Try again when neither of you have somewhere to be so your minds can be focused on foreplay.

For me this experience of the first time with a girl and my penis gets her attention is soooo good I get so horny, that normally I get very hard the whole time. But once it did happen to me as well and with one of the hottest girls I ever been with! I was nervous because of that and because we were together in class and I thought she was going to tell all her friends about that day. So it happened I got nervous and I went soft. Don't worry if a guy goes soft on you, it could be that he is nervous because you are very sexy to him, he just needs to chill out a little bit. :)

I think he was nervous about how it was going to be maybe his mind was elsewhere

I really don't think any guy would complain if you started touching his penis if you were romantically involved with him. Don't worry about it and try it again.

First, who knows why he went soft? My guess is he was worried either about his being late or your being new. Either way, it should pass IF YOU LET IT.

Which means, despite your instincts, you should bring it up with him, but in a good, supportive way. Don't mention his going soft. Instead, mention being happy to send him to work with a smile. That way, if he was worried about it (and we don't like worry, right?) he'll stop, and he'll feel better about you as a person.

P.S.: I'm always happy for forward steps in a sexual relationships. It's better to measure a trip by its milestones than by its speed bumps.

I have to agree with the answer above. Even if a girl doesn't know what she is doing, getting our penis touched is enough. Perhaps if this was the first time for this type of thing in your guys relationship he was just nervous. Has he ever gotten a HJ before? There are tons of reasons that might happen, but I seriously doubt is was because you were inaduquate.

I wasn't there, so I can't say if you did anyting wrong. But unless you did something dumb and actually caused him pain, it should have been a good experience. I think it was probably something else and not you.