I have this fantasy where I'm blackmailed or forced in some way to service a man behind my girlfriend's back. Maybe a neighbor who corners me and demands my body. I have a huge nipple play fetish, and could just imagine having to let him lick and suck me. Feeling shame and embarrassment while getting wetter and wetter. He would have me come over whenever he needed and offer him my tits to slobber on. Bonus points for heavy older men who know how to make a girl obey. After he's done using my tits, he should give me something to suck on. I want to be made to worship his cock, to serve his entire body and all his needs. Run my tongue all over him, his cock, his balls, even his ass and feet. All of this would be happening around my partner being at work, or asleep even. Having her wonder why I'm suddenly not interested in sex as much, because how could she satisfy me like a man could? Having her eat me out with a creamy pussy, and wonder why I taste so good.