I can catch a std from mastbauting my boyfriend and then myself?

Maybe: If you had contact with any secretions and he is carrying the germs of a STD they can be passed to you in this situation.

Probably not, but ..: Clinically, the likelihood to contract STD is low within the described scenario, but not impossible. Facts to know: Nowadays, many men and women might have multiple sexual partners in life, and nearly 50% of STD-contracted men/women are merely STD carriers without symptoms; furthermore, being exposed to STD-infected partners doesn't mean always contracting STD, roughly 15% of chance. This is life.