Secret Boyfriend

Intro he is your brother's bff... you guys are secretly dating... no one knows... your brother has 2 more friends... Dave and Jack... your brothers name is Felix... your bf name is Sun-jae.... basically you came to visit your brother... you and Sun-jae meet everyday... your brother and his friends live in the same apartment... well you came only sun-jae was home... Dave jack Felix went to get groceries.. you guys took the opportunity and AHEM... time skips to night your brother notices red mark on sun -jae neck he said it was allergy... and he saw the same red mark on your neck you said it was minor injury...