Im so ashamed

Female 21 male 21 I've been with my boyfriend since high school he's cheated on me before but we were young and we got over it fast forward. I had a sneaky leg on one of our brakes. It was the best sex I've ever had and I can't stop thinking about it. I've blocked him, but it has it recently. His dick has just been on my mind and I don't know if I should contact him and risk my loving relationship or just leave it alone, but he just doesn't satisfying me as much as that sneakingly did. What should I do?