"Thanksgiving" and "Smitten" - Janet Evanovich - 1988 and 1990
I had just finished "One for the Money" and spotted some short re-released novels from Janet Evanovich in the library's paperback section. I thought they might be cute quick reads that didn't involve guns and murder, so I picked "Smitten" and "Thanksgiving." All I can say is, "BOOOO!"
The men in these two books both fell in love by page 3 (only a slight, if any exaggeration!)
I know series novels are hard to pull off, harder than full length romances in many ways. Your characters have half the time to fall in love and the reader needs to buy it that they have. But both these boys are instantly infatuated! It didn't work for me at all - and I did not finish either book.