A masked man walks into a sperm bank, points a gun at the woman behind the counter and shouts, "open the safe!"
"But this is not a real bank!" the woman replies "it's a *sperm* bank."
"Open the safe or I'll shoot!" the man shouts.
The woman, now terrified, opens the safe.
"Now take one of the bottles and drink it.", he says.
"But sir, these are sperm samples!" the woman replies.
"Just drink it or I'll shoot!"
The woman opens the bottle and drinks the lot. "Now take another bottle and drink it."
"But sir, I just drank one!"
"Drink another one or I'll shoot you!"
The woman has no alternative and drinks a second bottle.
When she has emptied it the man now takes off his mask and the woman is surprised to see the robber is her husband.
"Now you see, Honey", he says, "it isn't so difficult, is it?"