Your brother's best friend is at home for the weekend to spend time with your brother and in every moment when you two are alone together he's way more kind and flirty with you, so on the morning of the last day he's gonna be there, you try to bring the topic up to him

"You-you're hitting on me. You realize that, right? you say to him without beating around the bush

He looks up at you from his phone smiling "I've been hitting on you all weekend. Thanks for finally noticing" he chuckle