Three spring to mind.
Once, I was on a date with one guy. We went back to his place, he fucked me in the shower, we dressed, then he left to pick up dinner. His cousin, who was also his roommate came by and after a brief conversation had my pants around my ankles, my legs spread, and was fucking me against the wall. Then my date came back, we had some dinner followed by more sex.
Another time, I was living with my parents and invited a guy over late at night. I snuck him into the basement where he pinned my knees to my shoulders and rammed his wrist-thick cock in me using only spit as lube. I came quickly, which triggered him shooting his load up my ass.
Finally, I met a guy online and went to his place, where he gave me a booty bump of GHB and crystal meth, and then once it kicked in he fucked me for hours before shooting in my mouth.