I have had a handful of sexual partners in my life, and have never had a yeast infection until my current partner and I became sexually involved.

I have now had 4 yeast infections in the last two years. Is there a reason I for this? Is there a way to prevent it?

Men can have yeast infections too, and keep passing it back to the woman.

Your body can be reacting to the antibiotics that you would be taking. When not taking antibiotics you need to take probiotics to replace the good bacteria the antibiotics depleted. Lack of good bacteria can leave the door open to getting infected again more easily.