Re: tight then loose?
It is normal for the vagina to feel tight at first, and then the muscles do stretch and relax. Combined with his erection diminishing somewhat after a bit, it might feel loose to him. You can tighten your pelvic muscles during sex or make fists with your hands and put them under your buttocks when he is on top. that will add to the pressure he feels from underneath you. It is very important to go slowly at first and be lubricated well so you don't tear and bleed! A longer foreplay time will help and you can always use extra lubricant if needed, available at drugstores. Some feel like the real thing, so you can experiment with different ones til you find one you like. Good old KY jelly works fine and is cheaper than some of the fancier ones.