I would add the word "all" before "over" to add some dramatic flair to the sentence: He made me so angry that I knocked my lunch all over his crotch. // Or --> He made me so angry that I intentionally spilled my lunch all over his crotch.
Crotch tends to sound like a lower, informal, register, so I would not use it with strangers. If you don't know your listeners that well, I would use the word "lap" instead of "crotch".