Mark spotted the guy across the bar and knew right away he wanted that cock in his mouth. Tall, built, with a thick beard and arms that bulged under his tight t-shirt. Mark bought him a shot, leaned in close, and said, "You look like you fuck hard. My place is two blocks away." The guy, who called himself Rick, grinned and grabbed Mark's ass right there. "Lead the way. I'm gonna wreck that hole."
They barely made it to the alley behind the bar before Rick shoved Mark against the brick wall. "On your knees, slut." Mark dropped fast, unzipped Rick's jeans, and pulled out a fat, veiny cock already half hard. He wrapped his lips around the head and sucked, tasting salt and sweat. Rick grabbed the back of Mark's head and thrust deep, fucking his throat in rough strokes. "That's it, choke on it. Take every inch." Mark gagged but kept going, drool running down his chin as Rick used his mouth like a hole.
Rick pulled out after a minute, yanked Mark up, and spun him around. He ripped Mark's pants down to his thighs and spit on his fingers. Two thick digits shoved straight into Mark's ass, stretching him open fast. "Tight little fucker. Gonna loosen you up." Mark pushed back on the fingers, moaning as Rick twisted them and added a third. "Fuck me already. Shove that cock in."
Rick didn't need more invitation.

He spat on his cock, lined up, and slammed in balls deep in one thrust. Mark grunted loud, the burn mixing with the stretch as Rick started pounding. No slow start, just hard, dirty thrusts that slapped skin against skin. Rick's hips snapped forward, driving that thick dick in and out of Mark's ass while he held him pinned to the wall. "Take it, you dirty cocksucker. Your ass is sucking me in like it needs this load."
Mark reached down and stroked his own leaking cock in time with the fucking. Every slam hit his prostate and made his legs shake. Rick grabbed Mark's hair, yanked his head back, and growled in his ear. "You like getting railed like a whore in public? Anyone could walk by and see me breeding your hole." Mark nodded, pushing back harder. "Yes, fuck me harder. Fill me up."
Rick picked up speed, his balls slapping Mark's ass with every thrust. He reached around and pinched Mark's nipples hard, twisting them while he drilled deeper. Mark's cock jerked in his fist and he shot thick ropes of cum onto the wall, his ass clenching tight around Rick's dick. Rick didn't stop. He fucked through the orgasm, pounding the spasming hole until his own balls tightened. "Here it comes, take every drop." He buried himself to the hilt and unloaded, pulsing hot cum deep inside Mark's guts.
They stayed locked together for a minute, breathing hard. Rick pulled out slow, watching his cum drip down Mark's thighs. He wiped his cock on Mark's ass cheek and tucked himself away. "Same time tomorrow? I got a buddy who wants to tag team that hole." Mark pulled up his pants, feeling the mess inside him, and nodded. "Bring him. The more the better." They walked out of the alley like nothing happened, already planning the next filthy round.