It can be, but sometimes having prolonged can also be quite irritating just to the vaginal tissues in general, particularly if there’s not enough lubrication, it can occur. It may not be a yeast infection, but having irritation in this particular area can certainly predispose you toward a yeast infection.
More likely this kind of itching and irritation is because of prolonged sex, so you’ll probably need to use a good lubricant. Coconut oil is actually quite a cool thing to use because it’s anti-fungal and it’s a good lubricant in general for sex.
Yeah, I would say you need to probably get yourself back in shape again and maybe next time you have sex don’t have it for a few hours, but take it easy and you’ll find that over a period of time it won’t be a problem anymore.