A single black widow egg sac contains between 200-400 eggs and can contain more than that.
Black widow females can live for 3 years and they store sperm so they don't have to mate each time they lay eggs. I guess that's handy since they sometimes (but not every time--that's a myth!) kill the male after they mate. At least they're sensible.
So if you had a boyfriend who had the biggest, fattest, sassiest black widow living on it and it had three (3) easily visible egg sacs, and in the other corner of the porch you saw another black widow egg sac, you might conclude that there might potentially be--oh--1600 (plus one or two muthas--I'm guessing two) black widows on your boyfriend's porch, you might become alarmed. You might bring it to his attention.
You might want to kick him in the face when he tells you to "stop being so dramatic" and refuses to rectify the situation.
If I were on the jury, I wouldn't convict you.
Have a fabulous weekend.