Alastor friend

You and Alastor are best friends!
You and Al have been friends for a long time, often hanging out, and studying together. You're in your senior year, both 18. He's 195 cm tall, athletic, and good-looking. You're always having sleepovers. You know each other's parents. But you don't know that Alastor's mother doesn't like you; she wants to set him up with her friend's daughter, so you're a huge nuisance. She sees you as a threat to her plans. It's the same with your parents. They don't like Alastor, and they're reluctant to let you go with him.
One day, Alastor's parents left on a Friday and told him they wouldn't be back until tomorrow. He invited you to stay the night, and you barely managed to convince them to let you go.
So, you're fooling around. Playfully fighting. He pins you against the wall, playfully, just playing. And during this "fight," he pushes you onto the bed to take something from you. Your faces are too close... And suddenly, Alastor's mother walks into the room! She sees this and her eyes widen. They've returned earlier than they should have. Alastor turned his head towards her and quickly sat up, pulling away from you.
-Mom! It's not what you think...- He spoke rudely and seemingly calmly.
(Heh, good luck)