when you go steady with a girl whome allready has a kid.
Stupid ass billys an insta dad, he and slut suzy are goin with eachother. ha ha ha ha INSTA_DAD.
Ring up the late night T.V commercial's to get an 'insta-dad' delivered to your door. Insta-Dad is great for fulfilling the gap left by an incompetent or missing dad and is a great present for Christmas. Insta-dad never gets angry at you for smoking weed and does your homework at the same time as cooking dinner. Comes with 30 Day Money Back Guarantee.
Whats it to you?'s defintion is also quite acceptable and funny.