Ladies with a lot of men friends may find this study very interesting… If you’ve been regarded as somewhat of a ‘tomboy’ for most of your life there's good news as according to a study published in the Journal of Comparative Psychology it has its advantages. 400 men in committed heterosexual relationships completed a survey that asked them to report on a number of different factors such as how attractive they found their current partner, how many male companions their partner had and how attractive they believed their friends found their partner. The results found that the men who believed their partner to have more male companions had more sex, something that the lead author on the study, Michael Pham, believes is down to a natural competitive streak in males, a concept they call 'sperm competition'. “A lot of work shows that men are sexually aroused by their partner when they estimate a greater likelihood of partner infidelity,” Pham told Fusion.net. “This does not mean that men want their partner to cheat on them. Rather, this means that if they estimate a greater likelihood of their partner’s infidelity, then they may (subconsciously) want to have sex with her to enter into sperm competition.” "We need to be reminded that our partner is valuable to us and desirable to others", Phams added. "This makes us keep working at maintaining relationship satisfaction. "Finding that right balance of inducing your partner’s jealousy will optimise a couple’s sex life".