Confront her. You need to know why she did that.

You waited until you could get your mom alone to confront her as you didn't really want to bring it up in front of your siblings and dad. After dinner, your brother & sister wandered off to do their own things and your dad settled in to watch some tv. You volunteered to help your mom clean up so that you could speak to her in private.

As soon as the rest of your family had left the room, you spoke. "Mom, I saw Randall at school today..." you began.

She interrupted in a soft voice. "Oh...I guess you know, then. I had planned to explain things to you before school but I just never got the chance?"

"Explain what?" you asked, your frustration showing in your voice. "How you lied to me and Randall in order to keep us apart?"

She sighed. "Sit down, Tim," she commanded in a resigned tone. You sat back down at the table and she seated herself across from you.

"Tim, I hated do that to you both - you know how I despise deception. But Laura" - she emphasized the name - "needed some time to accept and adjust to her situation. Frankly, you weren't helping with that." She seemed somewhat embarrassed at her admission but also quite resolute.

"Huh?" you said increduously. "What do you mean? Of course I was trying to help."

She shook her head. "You're being with her was NOT helping her accept that she's no longer a teen boy but instead a young woman. I'm afraid that regarding her dealing with the transformation and her new life, you were holding her back." She gave you a disappointed look. "Your behavior that first night demonstrated that quite clearly. Drinking and partying! It was very irresponsible." She sighed. "I suppose it wasn't surprising for teenage boys. But it was wholly unsuitable for a 29 year old woman with a 17 year old boy. Especially one who is her student!"

"But mom!" you complained. "It's not like that. It's Randall!"

She looked you straight in the eye. "That's precisely the point, Tim. It isn't Randall. She is now Laura Card, a young woman and your teacher."

You were almost speechless. "What are you saying? Do you mean we can't be friends?"

"No, no, of course I don't mean that," she said, reaching out to take your hand. "You and Randall were very close. I wouldn't want to break your connection. It wouldn't be good for either of you - especially her, as she needs friends who know the truth. What I'm saying is that you can't treat her like you used to - that will just make things more difficult for the both of you. She's a different person now and must deal with that. And you must help her. That means NOT dragging her back into old habits and behavior."

At your stunned expression, your mom's gaze softened. "You must remember that she is an adult now and your teacher - not your 'best bud'. You can remain friends - I think Laura Card will be an important 'family friend' for us all - but you can't have the same relationship as you did. Do you understand?"

You thought you finally grasped why your mom had kept you apart. And to some extent you even agreed - certainly Randall had changed and the two of you couldn't act the same, especially in public. But you weren't willing to give up your 'best bud' status, and you know Randall felt the same. You would just have to be more circumspect.

That made you think of the new 'physical' relationship you had started with Randall - you were already having to be secretive about how close the two of you were, so perhaps this wouldn't be any harder.

"I get it, Mom. Randall .... Laura is a different person and our relationship must be different. It already is" you said honestly, thinking about how things had changed once you had sex.

Your mom held your gaze for a few moments and then nodded her head, apparently satisfied at your acceptance - even if she misread your true thoughts.

"Good, Tim. I hoped you would - for Laura's sake. It's not like I would try to forbid you from seeing her. That wouldn't be fair - and, really, impossible to enforce. Just try to limit your interaction to what would be appropriate for ... well, for you and any other of our family friends. Keeping in mind that she's an adult woman and, of course, your teacher," she repeated.

"Got it, Mom. I will do what I can to help 'Laura' adjust," you promised.

She smiled at you. "You're a good boy... almost man, now. And a good friend." She stood up from the table. "Now, let's get this cleaned up."