Of the many factors that affect your compatibility with a man, one of the biggest (or smallest) is in his pants. As with humour, interests or habits, the wrong fit can leave you cold. Or traumatised. In a study of 1,661 penises, Dr Debby Herbenick, author of Sex Made Easy, found an almost nine-inch difference in erection size: from 1.6 inches to 10.2. And since absolutely nothing outside the package tells you what to expect with the package, you have to test compatibility the hard way. Sometimes you hit your jackpot, sometimes it's just fine, and sometimes he's the guy on either end of that erection spectrum. These writers have been there, so here's what they learned - and how you can deal (without the gasp reflex).