Oh how true it is. The other night I was thinking "she doesn't get wet like she used to." She used to be so wet I could hit her in the knee with my penis and I would score a goal.
i desided to love her up a little before I went down. We kissed for half and hour and she began shorting through her nose while we kissed. I put my hand between her legs and it was like old times. Now I spend the time I used to before I go down and give her three or four orgasms before we do the in and out as you say. She was her old wild self. Taking your time pays dividends.
As to frequency. There is an old joke about bean in a jar.
The first year your married put a bean in the jar for each piece you get. The second year start taking them out. SUPRISE it's going to take longer that a year.
When my wife was pregnant with our first She became extra horny. No threat of getting PG, no period, and an empty house. In two weeks we had sex 42 times and I thought that was something. I see we were behind the curve. Oh well---those days are gone--but not forgotten. And by the way we stopped because it wasn't fun anymore. It began to feel like a job.