Multiple orgasms for men are much more difficult then for women, in fact many men simply can not have more then one orgasm in a set period. He can increase his chances of having more then one by refraining from sex for 48 hours prior to the event. This helps, he needs to drink plenty of fluids such as water as well. Pop, coffee and alcohol will lessen his chances of achieving a second orgasm as well.
He should also consider wearing boxers instead of briefs as this helps as well. Keep in mind that the second time takes longer for males so he should not expect it to happen in the first few minutes of trying. Making sure the position is comfortable for him as well helps.
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