I think my neighbour is annoying but she's an easy lay.
Could you expand on why you would have sex with someone you don't like?
No, it's fun having a lot of sex all the time.
You shouldn't be with someone you find annoying. They could fall in love with you. Then you would have to hurt their feelings.
I'll deal with that when it happens.
I think you should be more mindful of your neighbor's emotions and how they might feel about their relationship with you. Casual sex is fine so long as both parties are willing, but there still needs to be mutual trust and respect.