That was definitely an unexpected revelation. For what's been a mainly light hearted jovial sort of story it brought up a very serious and heavy topic. It does provide some context to his curse but that certainly felt 0 to 100. I'm glad though for his developing years he was able to repress that memory.
For Lynette, I felt so bad for her, that's a real knife to the heart kind of moment. No matter the circumstances and his probably more innocent reasoning, I think it would be hurt any girl to be told she doesn't register as a woman. Even if she wasn't interested in him, while that may lessen the overall pain, it would probably still feel like a slap in the face.