I also found my sex drive has gone up in mid to late 30's at the same time my husband works oversea. I don't know if the fact that he works oversea and not seeing each other causing higher sex drive when we intimate or it is biological. The other thing may come into play though is we have more quality time together when we meet. All may come to play. He always has higher sex drive than me. I also find myself taking the time to enjoy more instead of are_we_done_yet? Haha.