Similar to "nip slip" a "dick slip" is when a man's penis slips through the hole in his boxers at an inappropriate time.

to send, or "slip", someone a picture of your dick, possible by several means one of them being through sexting

When you’re having sex and your dick slips out or in the wrong hole. Also meaning oops or you fucked up.

When your having sex and your tiny ass dick slips out of the pussy.

when you're fucking someone and your dick accidentally slips into their ass from their vagina