Re: How do I have sex with my girlfriend?
If your bed is against your parents' wall, the obvious solution is rearrange your room. Soundproof that wall if you have to, carpeting or egg cartons or foam packing material should work.
Otherwise, either one of you gets a flat, or you pool your money and get one together.
Dr. Howard, Dr. Fine, Dr. Howard: For duty and humanity! --Men in Black (1934)