When do you have intercourse in order to have a baby boy?

In order to increase your chances of having a baby boy you'd need to have sex as close to ovulation as possible - using fertility awareness methods and/or ovulation testing kits will help you determine the best time to have sex. This is because the 'male sperm' are faster than the 'female sperm' so will reach the egg sooner, but do consider that the 'male sperm' are also more fragile than the 'female sperm' so the acidic pH of the vagina is more likely to kill them off. You can help by making sure you're as aroused as possible prior to sex and use lubrication like pre-seed to change pH.