The lady asking me this question meant that while she has not much to complain about her boyfriend in general, in bed he is responding in a rather primitive fashion. When some sexual interaction starts, he is very rapidly aroused and finishes quickly, leaving her quite unsatisfied. Hence, the reference to a 'Neanderthal in bed'. 

To my experience, many couples have these kinds of issues when it comes to sex and many women especially complain that men are bad at sex. This basically happens because of a lack of understanding regarding the sexual biological differences between men and women in general (the exceptions making the rule). Men are programmed to spread their seed as fast as possible and thus they are very rapidly aroused and have an urged to finish off quickly. Women are programmed however to be usually aroused more slowly, so that they only engage in sex when the circumstances are secure enough for child bearing and raising a child. Thus men need to control their urges and give their partner the time to get into it. The men who can do this will then also experience that their own sexual enjoyment and orgasm is strongly enhanced. Women also need to understand men somewhat better and accept that hours of foreplay is so much going against men's biological programming that it may feel like torture. 

From Vedic science we can also learn that when sex is happening primarily from the love in the Heart Chakra instead of only from the sexual fantasies of the second Chakra, both men and women will experience much more enjoyment, even if this attitude comes more easily to women.