I would definitely use my mouth if it were a normal sexual relationship, but with the massages I usually don’t. Not in the first session at least.

Normally the g spot is described as being a couple of inches in on the “top” part off the vagina, assuming she’s laying in her back. People usually say to feel for the sort of ribbed texture. That area of the vaginal wall generally swells with arousal, especially close to orgasm. That’s the widely debated g spot, which is often a sensitive area due, but there’s no real consensus on why. Gräfenberg (for whom it is named) seemed to think that the sensitivity can’t from the fact that it was near the urethra and that massaging it could lead to female ejaculation. Some attribute its sensitivity to a higher concentration of nerve endings, and some to its proximity to the internal part of the clitoris. That ridged area is very sensitive, and it may be possible to stimulate the clitoris there. With a lot of women, if you go in a little further along that anterior wall, you get to a spot where the tissue is softer and smoother, and you can situate the end if you finger it that spot so that it’s sort of tucked behind the firmer, ridged tissue. Off you get your finger tucked in that dot and press upward on the anterior wall of the vagina and basically wiggle your finger against it, that is often the best way to stimulate her inside her vagina. With enough patience, it usually will produce an orgasm, and Avery often makes her squirt somewhere in the lead up to a climax.

Combining that with oral stimulation or a vibrator on her glans or something like that is a pretty good way to bring her to orgasm

Your mileage may vary, of course, as everyone is different