How do I tell this one guy I'm really sorry?

He is my best friend and we always play around and we both kinda like eachother but hes in a relationship so we dont go to far and he right now it's a distance friendship but last night I promised I wouldt go to sleep so I could talk to him because he needed to tlk to someone And I fell asleep :( he's pretty sad and alittle mad and I wanna show him really sorry rather than just say it. I've thought about a picnic but idk please help! Thank u! Xxx