Currently, I'm in a relationship with a girl I met online. Having said that, yes, the above posters are right. There
is a risk, and...I suppose "edge" provided in an online relationship is that one can filter everything presented about them. You need to be careful. I wouldn't say online relationships are 100% bad by any means (I love the woman I date now to pieces), but just know there are risks.
To the matter at hand (do forgive the above tirade), I fear you two will have long term compatibility problems with his view on sex.

I know you two aren't official yet, but it strikes me as a glaring red flag that as close as you two are described to be that he thinks it okay to continue things like this. I confess, I am not well versed in the BDSM subculture, but isn't there an inherent amount of sexuality even in "strictly business" play?
I am sorry...I am sure that isn't what you wanted to hear.

I hope things work out for you, and know I have you in my thoughts and prayers through this.