Simon Cowell -- Marriage Talk Makes Me LMAO

Simon Cowell might be over the shock of becoming a father, at 53, but his reaction to possibly getting married on top of that is down right hysterical -- as in ... "HAHAHAHAHAHAHA!!!"

Simon called in to "TMZ Live" to discuss a possible marriage to baby mama Lauren Silverman -- and his feelings about creating his own little Mini-Me.

Simon boasted ... "If it's a boy, then there will be another me on this earth for many, many more years to come."

As for his reaction to the news he'd knocked up Lauren ... "Gulp!"

But you gotta see Simon's response to the marriage question. Classic ... bachelor.