NEW YORK — Jennifer Lopez will soon marry Ben Affleck, but the muy caliente couple is leery of announcing their engagement. Bennifer did that nearly 20 years ago, then postponed the wedding four days before the ceremony, blaming “excessive media attention.” So this time they’ll try for secrecy, if they are smart, I’ve heard. As the not-so-secretive Lopez told People, “Before, we kind of put [our relationship] out there. We were naïve and it got a little trampled.” My source said of the second chance, “The big hurdle was their kids, but they seemed to have conquered that hill.” Affleck has thre…