Edited

Thrust, which is caused by candida albicans can be passed via unprotected intercourse.

I don't have much else to say other than to watch who your sex partners are. When one sex partner undergoes a parasite cleanse it is always recommended that their partner go on it with them. This is because these infections can be passed back and forth.

If one partner isn't cleansed they can continually reinfect the other.

Your boyfriend may have been an asymptomatic carrier for the candida. However, if he is passing it like this, I suspect that he may already be having some health problems or that he will be having them soon enough. Either that or he just has a great immune system and this infection isn't can't get to him yet.