WHAT IS A GOOD LIE FOR THIS SITUATION!? PLS HELP?! ?

Umm ok so my boyfriend wants some pictures of my b so i plan to send him one. Soo the day before i did a hickey on my just for fun . Haha lol and it kinda notices but not too much. Soo i keep taking pictures but it comes out . And i just send one like that to my boyfriend. Soo iam waiting for his answer but iam worried that he will ask me whats that or is that a hickey or are you cheating on me . Soo what are some good lies to tell him cuz i dont wannna tell him that i made a hickey on my own or should i tell him ?