What does "I love you" during sex mean?

I have been with my girlfriend for almost 3 years. I love her to death. But last night, I was really surprised by her reaction. In a very high moment of excitement during foreplay, I stopped to tell her that I love her and she looked startled and nervous. All she said was "what?". After that she said that she didn't understand what I said to her and that she does love me, and in previous occasions during sex she wanted to tell me that she loves me although she never did. Now, going back to what happened last night, I think she understood what I said, but she just didn't know what to say to that. Please I need some comments on this. How important is it to tell your significant other that you love her during intimacy/sex? After what happened, I feel very confused. I don't know if she really loves me or not.

In a very high moment of excitement, I doubt she even knew what planet she was on much less quickly comprehend and process what you had just said. Her first thought was probably "why the hell did you stop?" :D

I think that you are overthinking this, but I am a bit surprised that after 3 years together, that expressions of love from both of you are not common in your relationship.

Carl.

You fool.

If you've never said "I love you" before, you definitely never say "I love you" during sex.

haha, she probably wasn't expecting you to stop and say that.

I'm fond of saying "I love you" during sex... but that's just me.

As for her, she probably does love you but never thought to say such words during sex. Some people are just like that... sex is one thing and all other aspects of life are something completely different.

I think she was just surprised... after 3 years there should be other signs in daily life that you've noticed that shows that she does love and care for you. Showing this kind of affection during sex may simply be something she never thought to do.