she already had babies but both parents carried a gene that gave the babies a health problem so husband had a vasectomy so no more kids, but then discovered his wife was desperate for another healthy child, so set about trying to solve this problem.
Neighbour helps fix a loose pipe, as she mis leads her intention while her husband is away, only to get carried away by standing over him letting him see up her skirt, but what happened was far from expected and so was the result.