"EW, GROSS," Selwyn had just entered the common room and now he wanted to scratch his eyes out, except that would be even more gross than what he was currently witnessing.
"Haven't you two ever heard the phrase 'get a room'?" he asked rhetorically as he walked past them to throw himself down in one of the very expensive armchairs someone's rich uncle had probably donated to the House.
There, he proceeded to make loud retching noises over the edge of the chair. He'd just come from muggle studies where some Ravennerd had attempted to educate him on the uses of muggle technomancy. Like Selwyn was ever going to need to know that! And right before that lesson had been potions, during which he'd had to share a cauldron with up-the-duff Burns.
Needless to say, he was not in the mood to stand idly by while his own housemates attempted to get it on in the middle of the common room.