a tampon that is pushed inside a vagina. usually caused by both parties being overexcited and juiced at the start of intercourse that the hard-on easily 'tamped in' the tampon without being noticed.
I met a wild chick and we hit it off right away. By the time we got to a couch we were ready to explode. I was banging away and only later noticed the blister on my cock from rubbing against the ripcord all night. Guess I gave her a tampin. Hope she got it out the next morning.