Faithful husband fucked! How could I!?

My friend called me to ask if I could pick up her husband, she has to work late and can't make it. Of course I can! That's what a best friend is for! However, it had reminded me of how horny he used to fuck me... Well, the two of them had actually sorted it out after their marriage crisis and promised to be faithful to each other. Luckily it never came out that I was the one... Just the thought of it made me horny again. So I put on some fancy clothes and went to see him... I already have a bit of a guilty conscience that I fucked him on his construction site, especially when his wife called... Shit!!!