Bob the next door neighbour

A man is getting into the shower just as his wife is finishing up her shower when the doorbell rings. The wife quickly wraps herself in a towel and runs downstairs. When she opens the door, there stands Bob ,the next-door neighbour.
Before she says a word, Bob says ,

'I'll give you £800 to drop that towel.'

After thinking for a moment, the woman drops her towel and stands naked in front of Bob. After a few seconds, Bob hands her £800 and leaves. The woman wraps back up in the towel and goes back upstairs. When she gets to the bathroom, her husband asks ,
'Who was that?'

'It was Bob the next door neighbour, ' she replies.

'Great ,' the husband says, 'did he say anything about the £800 he owes me?'