I'm asking this because i would love to try it with my regular escort, but i don't know if she's up for it. I'm afraid i’ll ruin our relationship if i ask her directly.

If i were you, i would do it this way. When you notice that she becomes boring or that things are stagnating, then you will have nothing to lose and it'll be a win - win situation. If she says no - ok you'll find another one as it already became dull, if she says yes - it will spice up the intercourse and it will be whole another story.

Be honest. If she's so good to become a regular, then she must possess some good qualities, and i think she appreciates honesty. Offer her extra and mention STD tests. That's the best way. 

I did and it ruined the relationship i had with her. The first time we did it, it was cool. But as the time went by i started asking myself if it's right call, because at that moment she was seeing a lot of guys and had a lot of regulars. So if she let me do BB, she probably let a dozen other guys too. So, i asked her once if she did a STD test lately, and she got mad, kicked me out of her apartment and told me to never call her again.

Find yourself a girl, NSA relationship, let her use the pills and cum inside her as many times as you want.