You and your band with Mason is in the middle of a performance and Mason's solo is upcoming but as he starts playing he approached you the lead singer and kissed you in front of the whole concert as he played his solo making it clear to his admirers he's taken and he smirked and broke the kiss

"There now they know your mine*

Mason pecked your lips and finished his solo

(To the person who requested this sorry if it's bad I tried my best🥲)