When your penis freezes to avoid ejaculation while in the act of sexual intercourse or while buttsecksing.
by Jarryd January 23, 2006
 Get the Penis Lagmug.
Get the Penis Lagmug. When your penis becomes erect a considerable amount of time after being in a sexual or semi sexual situation
I saw a really hot chick at the bakery, but I had some mad penis lag, and didn't get a boner until I was down the block!
by jfitty359 August 30, 2019
 Get the Penis Lagmug.
Get the Penis Lagmug.