You are putting your marriage at risk though. You might do better by putting your energies into your relationship at home. New people are generally exciting but then after time has past they are no longer new. If they have it, it is basically a fibrous bundle of tissue about the size of a pea or a lima bean. We have no idea what it is for.
Some women find that stimulating that area is very pleasurable.
Some people think that stimulating the G-spot can lead to a different kind of orgasm than the kind of orgasm you have from stimulating the clitoris, but I don't think that is true. The G-spot was first reported in a book in 1982. Since then, no one else has discovered it. The G-spot doesn't get infected and hasn't been reported in any scientific writings. He hasn't seen it yet, and I'm afraid it will turn him off.